Mass social networks are influencer territory.
You do want the reach —otherwise you'd just make a group on Session with your friends or whatever.
The centralized platforms are a dictatorship of sorts but they make the often insufficient effort to include groups that hate each other.
If a Mastodon instance can become that centralized platform, I'll be the first to sign up.
People have also been conditioned to mostly trust whatever is on Wikipedia despite years of efforts to hammer it into people that this is not an okay assumption.
It would be better for there to be a bunch of Wikis that are competing with each other evenly. Having only Wikipedia is not a healthy thing.
... I mean, there _are_ (Conservapedia, Ruwiki, Metapedia, etc). It's just that the non-wikipedia generalist ones are so poorly run that no sensible person would ever use them, and usually have a fairly extreme ideological bent (there's a spectrum; Metapedia originally showed up because Conservapedia was insufficiently delusional for some peoples' liking) which requires them to wholesale make shit up (as the old joke goes, reality has a liberal bias). However, if Wikipedia ever goes all evil, I would assume it'll just be forked (there've been a number of prior forks, but except for Ruwiki they've generally died due to lack of interest).
There are, honestly, serious economies of scale here. Unless Wikipedia actually has gone evil, well, no-one actually wants to maintain 66 million articles (No-one, say, wants to maintain 14,000 articles about bridges: https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Bridges_...). Specialist wikis work, but it'll take something fairly dramatic to break Wikipedia's dominance.
(In an ideal world, I think this _would_ be more decentralised, but it's just very difficult for that to happen in practice. I think much more difficult than social media, which has never really _fully_ centralised in the first place.)
Unfortunately Wikipedia exists within a collective blind spot, so I am not expecting the situation to change. At most people will drop Wikipedia in favor of LLMs, which is even worse.