Niggas dont pay for porn because it's free elsewhere on the internet. If those avenues didn't exist you'd see the resurgence of adult video stores again. Am I gonna pay $6.99 for a 30 second vid or go to Pornhub or Spankbang and see the same vid someone uploaded or another for free ? Easy choice.
OnlyFans is trying to go public and raise money. Their investors don't want to fund pornography because in other places around the world (like Japan, Russia and China) they're extremely strict about porn. If OnlyFans doesn't branch out then sure enough, companies like Facebook/IG, Google, Apple, Amazon, WILL create a non-porn OnlyFans which is currently in the works. It's business, you either adapt or go extinct.
Those sex workers are entrepreneurs, they should be used to challenging business cycles. You can stomp your feet and whine or you can find another way to thrive. There's way more options than they think. Some good things come to an end, unfortunately OnlyFans for sex workers is one of them.