In general, this is true of the broader population as a whole. Mastodon got the size that it’s an actual place (and I think this applies to lemmy/threadiverse too). But it’s by no means “THE place” or even categorically a big public place. More like old-school forums that have a particular user base and vibe that you visit from time to time.
For the fediverse, the “migration” was exciting and successful, but compared to big-social, a drop in the ocean. And the biggest clue for that is that the people most excited about Threads joining the fediverse are Evan (author and lead “advocate” of ActivityPub) and Gargron (masto CEO/founder) … they want to taste that big-social scale and know that they don’t have it and likely never will.