I think this misses the cultural shift around the popularization of the web/Internet.

There used to be a high barrier to entry for creating content. The folks who were capable and willing to surmount that barrier posted stuff that nerds like us enjoyed. It was really hard to monetize (unless porn), so it was typically free.

Then social networks came along and made it easy for everyone to post. Just like normal society, the non-nerds started drowning out the nerdy early adopters.

Certain networks became cool (Twitter, Medium) because cool normies were on there (aka the network effect), and that pulled many nerds of self hosted software.

Other social networks were monetizable and incredibly accessible (YouTube), which pulled many other nerds off self hosted software.

Proprietary networks suck morally, but they’re incredibly easy to use and democratizing. That cranks their network effect to 11 and makes the old school web less rewarding.