I never really ‘got’ Tumblr, the only reason I joined as at the invitation of a woman I’d known through another site and whose art, music and philosophical group I liked to support. Since she died tragically young I haven’t visited often. Can’t say I ever saw any adult content of any kind but then I wasn’t looking.
It’s always sad to hear of another side that supported free speech while having an understanding of what free speech actually means is going down the pan, but censorship of web content is becoming more and more widespread. It looks like the dark web is going to be getting a lot more users in the future.