When Twitter was bought by Musk I rushed to create myself a Mastodon. My hope was that most of the interesting, thoughtful people I followed on Twitter would eventually end up on Mastodon as Musk slowly ruined the platform. I kept my Twitter up just to keep tabs on them and grab their Mastodon handles as they shared them.
In the end, around half of them created Mastodon accounts that I follow to this day. All of them are inactive now.
At the same time I noticed more and more of them creating BS accounts. I think around 80% of them ended up in it. They're still quite active in BS to this day.
I open Mastodon and BS once daily. Former rarely has new posts, latter always has.
I really wanted all of them on Mastodon. I don't trust a corpo like BS. But the particular type of crowd I followed on Twitter (progressive essayists/humanities people, game journalists, artists, non-dev hobbyists, etc) seems to have mostly gone to BS, stayed on Twitter, gone to Cohost or back to Tumblr, or abandoned social media. I did find some interesting people active on Mastodon, mostly accesibility advocates, a couple of devs of games I loved and a few non brainrotten IT people. But the level of activity from my spheres of interest seems much higher on BS right now sadly.