My ex-girlfriend was a pretty active pornblogger on Tumblr(her own content and reblogging other stuff before it got shut down), believe me there was a pretty big porn community on there, although it's broken down into pretty specific niche categories(like DDLG, CNC, BDSM, etc), but within those niches there's lots of active content creators that are pretty well-known within their little Tumblr social circles.

warning possible triggering content ahead Example, this one guy ran a blog called "Rapebait Academy"(CNC fetish, Google if you're interested I'm not gonna get into that here) where he could post pictures and videos of him with the girls he would meet of Tumblr and what they got up to together(with their consent of course). And anyone who was involved in that little community on Tumblr knew the guy and who you were talking about if you mentioned his name, or at least his blog.

So there's definitely people interested in making content on the platform, people interested in consuming the content, and there's always gonna be people willing to pay out the nose for personalized niche specific content, which will be easy given how Tumblr is a directly creator-to-user platform.