To be honest - Lemmy migration made me an active Mastodon user.
I joined Mastodon right after Musk took over Twitter. I was never big on Twitter but wanted to try mastodon.
But never became active. Because I was not a tweeter. I was also not a tooter.
The Reddit exodus was a wake up call for me and I committed to become a user and supporter in fediverse. So the migration to Lemmy/Kbin activated me as a Mastodon active users.
A lot of people left due to it not being morally sound for them to support Musk and his actions.
But now there are paywalled features that are ruining the functional experience of Twitter. You can’t look at the site for more than half an hour before getting restricted on a free account
Plus Mastodon has had time to polish instances, apps and gain a userbase so it is a little easier to transition
I mean, each time he's messed it up more, another group of people migrates off twitter over to alternatives. I also think more people in general are becoming aware of the fediverse in general thanks to what's going on w/ reddit, but that's speculation on my part.