OnlyFans doesn't want the smoke. They are doing well and could change the whole industry. But the owner knows the shady shyt the business is involved in. Yeah MasterCard wants them to jump through hoops, but so does every other porn company. At the end of the day they, even though they require each content creator (sex worker) to have the proper ID on file for everyone on video, it is still a liability. Craigslist shut down it's entire personals section in the USA because Congress said they would be liable for any sex trafficking occurring on the site. OnlyFans doesn't want that smoke. That would also be a lot of administrative stuff on their end, and everything that infrastructure entails, and that's more money.
But they should just do it because OnlyFans is officially associated with porn anyway. You can't even really use Tumblr as a comparison, because Tumblr still had a lot of non sex related blogs. But let's be real. All of those sex workers are able to make the money they are because OnlyFans isn't on the up and up. So they are able to charge so little and still secure the bag. If OnlyFans acted as a legit porn company, with the creators being independent operators, they would probably end up taking a bigger chunk of the profit sharing. Which would mean the creators would have to jack up their subscription prices. Which would just lead to more people stealing their shyt.