People will just go to other websites. There's plenty of established companies waiting to get a piece of the action. I honestly wouldn't be surprised, if OnlyFans decides to go through with it, PornHub is spins the wheels on getting a platform launched to compete. They already got an established development team and they are well funded. There are other established sites out there right now with worse UI's as well, but it will usher in a whole new era of online sex work. No need to panic.