I think this is going a bit too far. Sometimes it's perfectly legitimate to serve an ideological need, because there's enough people with that particular ideology.

Eg, things like Mastodon are great if you want to find a community that best fits you, because you have a rare interest or some characteristic controversial for a reason or another that makes existing on some place like Twitter difficult. So you can find a community that enforces standards that are very close to your ideal, and delegate that to them, and just do your own thing.

Not everything has to be like Twitter or Facebook, aiming to swallow the entire planet. There's room in the world for places like Hacker News that are only relevant to a small segment of the population. What's important though is to have a good sense of perspective about what need you're serving and how many people are there who need that. If you're aiming for something like decentralization that will have some costs to it that means you're unlikely to ever go world-wide. But so long you're happy enough with that, there's nothing wrong with it.