@gabriel I think the bigger problem though IMO, is "will people do shit".
What wasn't mentioned in the thread (because it focused on the RW aspect) was when Tumblr's userbase had their toys taken away, first with the 2018 porn ban and now today with the remaining users being some of the most caustic people online (and literal pedophiles, I'm not even making this part up).
While everyone spilled over to shit up Twitter and the rest of the internet, what isn't talked about is how none of them actually tried to "build your own" site. Even though the right did and got squashed over and over again or had to deal with life on ultra-hard mode (see: the state of KF right now), with Tumblr nobody tried or the alternatives have done worse than shit like Gab has.
No seriously. How is Pillowfort doing? Or Wafrn? Pillowfort is still "pay to sign up" and Wafrn is niche as shit in the fedi/bsky realm.
One of the biggest social media sites for a while literally got wiped off the face of the earth, has an audience where they had it on EASY MODE when it comes to the idea of "building your own site", and still couldn't do it.
Copying Tumblr 1:1 is a bad idea considering that IRL nudes are a legal minefield, especially given the population the site had. But if you had say a place for NSFW artists to post it'd attract the same types.