I just mentioned them because they're microblog sites, so in theory they do the exact same thing as Mastodon. The number of Mastodon users doesn't matter; the number of people on Fediverse platforms compatible with Mastodon matters.

So Lemmy users are not very helpful, but Mbin users maybe more so. Or Friendica.

The point is just that the number of Mastodon users is, in theory, irrelevant, as you don't just communicate with Mastodon users. Maybe misskey was a bad example, I don't know anything about it.