Blaze (he/him) This is the real issue. The majority of people do not want to build community -- hell, they don't even want to be in a community! -- they just want to consume content. They'll comment on content, because they want to be seen and because 500 other people are commenting, but they're not interested in doing anything proactive.
This is why the network effect is so powerful. It allows you to be a passive consumer of social media, rather than a real participant in anything.
There's a lot of hand wringing on Reddit these last couple of days following the announcement that Reddit is going to block access to people who aren't logged in, but seemingly none of the people who are complaining and calling Reddit "over" have any interest in building something new. The question is always "is there a viable alternative?", and not "where can we build a viable alternative?"
And that's the forever problem of the Fediverse. There's seemingly no one to build the social infrastructure. Everyone here who's interested in building something is a software engineer, not a social engineer.