... who are in a committed relationship that is worth saving but lacks intimacy: escorts meet that need without having to give your heart to someone else.  

Maybe that's obvious and thus not stated in the OP, but all of the benefits stated in the OP are obvious to me.  

Let's do a top ten, shall we?

10.   She just loves the size of your cock no matter what size it is.
9.   She dresses up for you.
8.  You don't have to get dragged through a mall, unless you want to.
7.  You get to decided what to watch on TV, movies, etc.
6.  You get to pick where to eat.  (Within reason)
5.  Perfume....yes perfume!
4.  Her stuff isn't all over the place all the time.
3.  You don't get asked about what's new at the office.
2.  You don't have to meet her friends.

And the number one reason escorts are better:

1 You can leave the seat up

an affair where you run severe risks of problems with her wanting too much of your time, wanting to talk, text, etc. at all hours, many of which are not convenient.

Also, we pay providers to leave. Again, NSA good times. The key is to not cross the line. Providers are not RL dating friends.

Where else could a guy in his 50's or 60's get between the sheets with a hot 20, 30, or 40 year old hottie?

Not that there is anything wrong with dating hookers, I have dated a LOT of them, but there is a big difference between hiring a woman to be with you for a short, defined period of time and actually dating that very same woman.

With atf relationships I love all the extra stuff. Emails, vms, breakfasts lunches and dinners, freebies, texts, conversations, and all the naked pics she sends that she can’t post here or on her website.  

With non atf relationships I love finding the ladies that fit my sexual desires to a tee. If you love big tits, you can find them. If you love small tits, they’re available too. If you’re old school and love hairy pussy, your fetish will be taken care of. If I only want a quickie bbbj, I know who to call. Also, if you have a particularly wild fetish, you might be able to find it here. I’ll never forget the time her mouth was completely at the hilt of my cockshaft, and I literally came down her throat. A rarity indeed. Haven’t found anyone else who could, or would do that, but I did get to experience her twice before she was gone to TER oblivion.  

Lastly I love the variety of fbsm experiences available. Sometimes I want it to be all about me, and I go there. If I want a straight massage without the happy ending it’s cool. I’ve also had massages get a close to full service as one can possibly get without going over. That’s cool too.  And of course, I’ve had them surprisingly go completely full service, but only when she really likes you. The ones when you least expect it are the best.  

With all of that said the greatest fun about dating escorts is the discovery of women. Each one is so different it’s like starting your sex adventure over and over again.

You can keep and maintain the "Family".

You can have access to Many beautiful women.

Probably better at intimacy than your wife.  and YES, I DO love my wife but she's a neary total bust in bed.
Available if your wife decides that she's no longer interested.

I have met and enjoyed the ocmplany of many rule charming, beautiful, and sexy women who seem to enjoy my company and definitely want tomato me happy.  
No small thing.