In the grand scheme, though, no one uses either mastodon or lemmy. I'm sure, to the devs and people who joined before 2021, that a couple million users seems like an enormous victory (and it is), but relative to a half billion twitters, the 1.5 billion instagrammers, or even the 5+M that signed up for Threads on the first day, it's nothing.

Those Threads users aren't part of Lemmy or Mastodon, they're part of Threads. They don't have to know what Lemmy or Mastodon are, even as they benefit from content created there. Once Threads is big enough, they either DOS non-corporate instances with mountains of data, disable those instances with protocol-breaking customizations, or just ignore them because all the biggest communities and content are hosted at Threads.

When mozilla & google started working together, Firefox was the majority browser and chrome a ridiculous upstart trying to squeeze into a domain dominated by IE and FF. The fediverse does not have mozilla's power in that analogy. I mean, fediverse may survive after that, but the commercial players will absolutely siphon off anyone who cares more about the user experience and content than about privacy on a public forum, which probably means the user base of July 2022, not July 2023.