And even if they were, the community is gone, and you can't just rebuild that.
That makes it different from Instagram which is focused on original content with little discussion. Reddit which is focused on new content with much heavier focus on discussion. Facebook which is supposed to be for personal content with familiar people.
Not necessarily if the reason was (as people think) to avoid SESTA-FOSTA legal problems. Pornhub would still need to work around those restrictions and it might simply not be economical.
I also heard the rumor that PornHub was interested in buying it. I hope they do! Can you imagine how quickly all the corporate blogs would scramble off of the platform to avoid association with a porn site!?