Both of the current culprits mentioned above Host with Cloudflare.
Yes, OnlyFans creators are likely losing millions of dollars a month to these sites but there is a greater issue of this content being consumed by groups of people who OnlyFans creators never intended to be seen by.
Xvideos is another site where you can easily search the name of popular creators and their OnlyFans videos and pics come up instantly.
All of that money is kept by those companies to continue to grow and expand legitimate businesses.