I've been on mastodon for 4 or so years ago, it takes a bit of time to build up people that you like to follow, which is really important on mastodon, since they are your algorithm, I find new people from the boosts of people that I know and trust, find new interesting people, and my feed is so full that there is always something going on, and I don't really have a chance to read it all.
I'm also not really into "high-profile" people, so I guess that helps as well.
I think they had around 25k people signing up to be notified when the sync for lemmy app releases, so at least some of them are there :)