It seems there are limited options on weekends, except agencies which I don’t prefer.

Why is that?

I was looking for 2-3hr incall or outcall today and there aren’t many options or availability.

One would think weekends are the best time. Personally, I find it hard to date during the weekend due to work and life.

You answered your own question.

Meant to say hard during weekdays.  

Still can’t find anyone today which is annoying since I’m very free.

I would think that weekends, holidays, etc are the worst times for providers. Since the majority of clients are married and have families those days are probably the toughest to get away.

I understand the OP's frustration. Touring providers will often hit my area in the middle of the week. Booking with her would force me to take the day off work and I'm not fond of that. For me it has to line up on a weekend or a day in the week that's an election day or some holiday when I'm off work.

I get frustrated when they come Friday through Monday - I can't usually make that work at all.

I found weekends the easiest to book anyone.  Independent or agency.  But, if you're looking for an independent the meeting needs to be done 2-3 days beforehand.  Check who's touring in town and reach out.  Same day on a weekend you can get lucky sometimes, but overall planning is best.

You have to prebook.

Many indys do all of their own screening and "bookkeeping".

They're only human.  Just like me, unwinding after each workday when the markets close at 4pm.  
One popular regular provider I see, doesn't take weekend appts.  She goes hiking, biking, and going out with her GF's.  

Gotta separate work from personal life, right?

Some are at it 7 days a week. I don't know how they do it.

Qos (quality of service) goes down.  They need to take some time off. As they mature they will take time off especially on the weekends.  But don't be fooled they could be having a overnight or weekend with a client and start back up right awa.