Why do the men that participate in this hobby stay with their significant other?

Your needs are not being fulfilled .I don't lie. I prefer to tell the truth. The reason why I continued with this hobby because what everyone won't do someone will happily with a smile. 😊 😋

I stayed  mainly because I was raised strictly catholic and divorce was not allowed, and I wanted our children to have two parents around.  We did a good job as parents.  I'm now agnostic.  I would never have stayed if not for the catholic upbringing.  I would go to mass, say rosaries, light candles, pray for our marriage to thrive.  Praying to a garbage can would have gotten me the same result.  

We could decouple love and monogamy. Love, friendship/companionship, sexual attraction and sexual fulfillment are all different things and being complex human beings who grow/change over time it's ludicrous to think that one single human can be IT in each department for a lifetime. So much unnecessary stress is caused by trying to force this delusion onto society. In my fantasy world, we'd be much more like bonobos than chimps (equally close in DNA but opposite in social structure).

And ordering the exact same or similar meal. For some, that consistency is comforting and satisfying, and if it genuinely fulfills them, then good for them. But I really question whether it is based in human nature or some other pressure from outside.
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When you examine other areas of life, exclusivity is rarely treated as something worth pursing. We make multiple friendships without diminishing the value of any single one like a bestie. Many of us favor a particular store, but their competitor will, on occasion, attract our attention. Think of travel. I love going to Europe but a trip to a great beach just 2 hours from my home can be great fun too. Why should sex be different?
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One of the most appealing aspects of p4p is the smorgasbord appeal. lol. It allows for unique, differing experiences with vastly different women while still allowing for someone to return to a particular provider with whom they share a certain sexual chemistry and/or personality attraction.
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Monogamy was implemented by religious institutions. However, the recurring pattern of infidelity, even among prominent religious leaders who espouse monogamy at every turn, should tell us everything we need to know just how really impossible it is for most. lol

My ex loved to discover new places to eat--usually very pricey. Had to go to the hot new place at least a couple of times each month.  
But at home, it was the same vanilla sex routine (when there was any at all). Doggie was considered so wild that I was only allowed to venture there about once a year. And forget about oral.
So not only the same restaurant and same meal, not a particularly great meal at that.

for NOT staying with her.  Most of your points support separating, not staying together.  Divorce is the nuclear option, and it will be expensive and there will be collateral damage, but wouldn't you rather be with someone who enjoys sex with you, can't seem to get enough due to the experience you gained in P$P, and has a hot, younger bod than your wife has?   I have been where you are, not with a wife, but with an SO, and scrapping it all for someone younger who really enjoys sex fixes most other issues that might come up.  

since I'm a woman. But I stay with mine because I truly love her and I love her company. But I also love sexual variety so my liasons with providers are simply hot sex with pretty girls that I hope are mutually enjoyable. It's as simple as that.

We married later in life, each had our own established life/career. We're compatible in every way. Except sexually.  Even when it was good, it was just acceptable, never mind blowing. I don't think she really likes it to tell you the truth. Physical sex stopped 10-15 years ago.

For incisive thoughts. I may have stayed with my ex if I'd just figured that out. Maybe.

ex not knowing what you are doing.  Lopaw has it right, but it's the secrecy, once discovered, that kills the relationship, not  the fact that you are engaging in recreational sex outside your committed relationship.  99 out of 100 woman would consider it cheating, not because of the physical aspect, but because you kept it from them.  

....and divorce would be so disruptive to the lives of many others as well as mine.  

The disruption of other lives is the biggest issue for me.  If my wife would ask to go be with other guys I'd say have at it.  I've been avoiding divorce for several years but now I'm starting to consider it.  Just getting tired of this situation.

I think people's sexual/relational styles (and most everything else) exist on a spectrum. Some people are naturally (sans societal programming, if that's possible to conceive) monogamous - they meet their "soulmate" in kindergarten and have an amazing, healthy, fulfilling, lifelong sexually/emotionally monogamous relationship and can't imagine it any other way. Good for them! Seriously. If we all were built that way NATURALLY then life would be MUCH simpler, wouldn't it??  But reality says that we're not. And there are people on the other end of the spectrum who have no interest in being sexual with the same person twice and emotional connections spark and fade like fireflies at dusk. And THAT is them being the most true to themselves and is just as valid as anywhere else on the spectrum.  
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It's the forced monogamy/nuclear family stuff that screws everyone over that isn't NATURALLY on that particular end of the spectrum.... and here we all are!🤣
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Tho.... countering the spectrum idea is that lifelong monogamy would suck for genetic diversity/resilience and doesn't make evolutionary sense so I'm not sure how many humans would actually be hardwired from birth (not softwired from conditioning) to choose monogamy. 🤷🏻‍♀️

My most recent X started out fun enough but around the second year he settled into a routine with frequency going down to about 2x/wk. Ok, it's understandable that it's not going to be crazy, hot and heavy forever.... But by the third year, having sex anywhere but the bed was out of the question, and even LAYING SIDEWAYS on the bed vs the regular way was sure to kill his mood, with frequency going down to about 3x/mo. By the fourth year, the activities were reduced to a very small "script" that centered his needs (leaving me to finish myself 90% of the time) and frequency reduced to about 12-15x/yr. I stayed 3 more years thinking *I* was the problem🤦🏻‍♀️
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I'm soooo glad I have the freedom to do ALL the different things, with ALL the different people that I want now😇

Same here.  I'd go as far as violating my own one-dick rule if she'd want another guy to join.  No sword crossing though, lol.   Anything to step out of the vanilla only sex.

It's not a one-sided situation. As I stated, she probably has a guy on the side as well and I'm ok with that.
I'm not stopping her from doing whatever she wants.

getting to do whatever YOU want?  If you met a really hot provider, are you in a position to ask her to leave with you the next day for a week in Hawaii, or would your wife not stand for it?  If it wouldn't be possible, then why are you still married if YOU don't get to do whatever YOU want to do?   The answer is that there is financial component to being married that some guys are afraid to disturb.  Two can live more economically together than they can apart, and that's the reality of situation for the majority of married guys who see providers.  

I get what you're trying to get across and to a degree I would agree but I only have a sexual interest with these other women. I would never consider going on a trip or an overnight visit with a provider. I would enjoy that so much more with my wife.
Like I've stated before, my wife is the absolute best women on the planet bar none!!!!
This woman til this day would get up out of a dead sleep to make something to eat even if we are in an argument.
I'm going to do what I can to keep her but if she decides she wants to leave...I get that also and wouldn't stop her.

What am I gonna do date gold diggers or other ole
Women.  Or just marry someone else.  Mines perfect.

I can't decide if you don't deserve her, or she doesn't deserve you. . . . . . for different reasons.

10 million reasons why

Like the guy that mention different restaurants, my wife and I both need that.  She’s cuckold me and only plays with black guys and has regular lovers.   She thinks or pretends to believe I don’t partake in other women but I too like variety sonInsee escorts
It works for us.

I promise to take care of you much better than that!

Back in the day my wife and I had great sex, she's a still a hot blond who can easily wear her wedding dress. She hits the gym three times per week. On the other hand her desire slacked off several years ago. I could ask her to  fuck at anytime and she would engage. Her bodily functions are not the same or desire. Pretty sure she knows I see escorts from time to time and is kind of OK with it. I am very careful to make sure none of this enters her lifestyle. We still have a great history and life, more like best friends who don't fuck. Probably sound strange to others but we are both 60 + yo.          

There is at least one frequent poster on The Erotic Highway board who is in an open marriage. He is a Sugar Daddy (to women) and his wife is an occasion Sugar Mama (to young men). Everything is out in the open, the wife knows that he sugars and even gets to meet or know some of the girls.

Yeah, that's another reason.  I figure together we'd have at least a couple million more for retirement now if we'd stayed together.

CDL is the self proclaimed expert on everything, including your relationship. Case closed!