You miss the point.

What if you want to have a Facebook with the name “Joe Smith” and an OnlyFans with the name “Queen Georgina”? Even if your OnlyFans shows your face - which isn’t a requirement by the way - it’s not your real name. And you may not want to put your face or your real name on your Facebook at all, and keep the two completely separate.

OnlyFans basically destroy the separation between your accounts and links both with your real identity, your real government-issued ID number or SSN. And they collaborate very closely with Facebook in case you didn’t know. I know that because I asked them.