I've never actually logged into and seen anyone's Onlyfans page. I have to think, though, that it is like anything else... in that the market gets watered down pretty quickly and only a handful of folks at the top of the pyramid make any real money at it. Oh, and don't think you have to be the prettiest to succeed either. There are fetishes and all kinds of surprising personal preferences plus personality and whim that play a part.
There are a lot of talented artists and actors and musicians who aren't making a dime. Some of them even have history or name recognition but still can't catch a break. Onlyfans should be no different. If you get in on the ground floor you have a captive audience even if you aren't the best. When it gets popular some talented people show up and take some of your audience away but if you are good at it you can probably still do okay... but at some point it quickly becomes a market that really can only sustain a handful of top tier money makers and leave only crumbs for everyone else.
When the iPhone first came out I started looking into writing programs and selling through the app store. I'm a decent programmer, if rusty, and it didn't take me long to be able to make programs that worked. Problem was, I was late to the game and missed the early window where apps were in such demand that anything would sell. I was competing then against people who had nothing but time and love for programming who put way more effort into it than I was going to be able. So there was no point in me pursuing that any farther than just a hobby.
On the moral side of things... I don't know how I'd feel about it. I have no qualms about looking at the nakey, and especially in my situation where the only way I get to see naked women is through adult entertainment... and I don't judge people for whatever they want to do, especially when I'm willing to partake. But I don't think I could do it myself, even if I thought there was a market for me.
Random tangent... one escort that I saw way way back in the day... she randomly told me that I could make money if I wanted to work as a male escort. Now, I know you take all compliments with a grain of salt when you're paying for an "experience" with an escort... but usually that's "you're so big" or "you're so great" or whatever... not, hey let me know if you ever want to do some work. Assuming it was a legit offer, at the time I pretty quickly put it out of my head as an I don't think I could do that. As someone else said, OnlyFans if you do solo stuff only is something you can detach more from I suppose.
I don't think I could do it, though.