It is a zero-sum game in some sense, because you go where your friends or "influencers" are.
Mastodon ended up losing its user base to Bluesky during the early Twitter exodus because many influencers and journalists wanted to have an "elite" status and a special relationship with the platform, so they preferred a platform owned by Dorsey to some hippie open-source thing. Bluesky, in turn, ended up losing back to Twitter/X when it turned out to be a place where you mostly talk about how awful Twitter/X is.
I want to say that we don't need social networks where we constantly interact with hundreds of thousands of strangers, but I'm writing this on HN, so...
Mastodon ended up losing its user base to Bluesky during the early Twitter exodus because many influencers and journalists wanted to have an "elite" status and a special relationship with the platform, so they preferred a platform owned by Dorsey to some hippie open-source thing. Bluesky, in turn, ended up losing back to Twitter/X when it turned out to be a place where you mostly talk about how awful Twitter/X is.
I want to say that we don't need social networks where we constantly interact with hundreds of thousands of strangers, but I'm writing this on HN, so...