Why did they get rid of porn anyway?
Tumblr was acquired by Yahoo! in 2013. Since Yahoo!'s business model was mostly built around self-harm, the annihilation of creative joy and the corporate strategy to create a large, Yahoo!-shaped smoking ghetto in the middle of Sunnyvale, CA, it's not surprising that Yahoo! ordered Tumblr to remove all the content that could accidentally generate traffic (while leaving Taylor Swift.)
While this is no doubt true, I think the porn thing had something to do with SESTA (the bogus "sex trafficking" bill that essentially made sites culpable for things their users post directly, as opposed to only if they didn't adhere to due diligence to investigate reported infractions - a horrible precedent). There may have been other issues as well, including some degree of rebranding and definitely Yahoo self-destruction, but I think there were other options specifically related to the adult content.
I don't know the exact details, but having followed the rise of the "Fediverse" open source, federated alternative social networking platforms, there were many new Mastodon (ie joinmastodon.org - a better-than-twitter-like microblogging platform) instances spun up in the wake of Tumblr blocking porn, including one named "Humblr" if I recall, and one called "Switter" which is specifically noted as sex-worker friendly for all the escorts and the like that used to advertise on Tumblr, Craigslist etc... before SESTA caused those sites to kick off adult content - so they basically created their own!
The actual newsworthy part of this is the price.
Tumblr costed 1.1bn $ with porn, and now without it's being sold for less than 3m $.
So, porn is worth over a billion dollars, because "The Internet is for Porn!"