We had a very brief window when the Twitter Exodus was happening and non-techies were giving Mastodon a try. But it wasn't good enough, as far as giving the Twitter refugees what they wanted to see, and so they simply moved on to the nearest Twitter-With-The-Numbers-Filed-Off platform and stayed there instead.
There's probably a good post-mortem study someone could do on this (someone more tuned in than me, since I never had a Twitter account to begin with), and the larger ramifications for why many of the FLOSS platforms fail to gain the adoption they think they will when the flagship proprietary platform becomes intolerable. cf: the failure of Windows 11 refugees to move to Linux, Chrome refugees to move to Firefox, etc.