I am always a little surprised that everyone is surprised as if people are intentionally avoiding Mastodon.
I like Mastodon but it is empty by comparison to BlueSky people want a social media app where there are people to talk to on quantities. BlueSky is also user friendly by comparison, IMO. Easier to setup.
"Well Mastodon would be busier if people would stop going anywhere else."
No one is avoiding Mastodon I think it is odd it has never occurred to anyone that BlueSky is talked about way more. I had never heard Mastodon before Lemmy but I saw talks of BlueSky everywhere.
I use both Mastodon and BlueSky and I don't really care for platforms like Twitter. Both Mastodon and BlueSky are good in their own ways but I think BlueSky is user friendly. Easy to setup looks super similar to Twitter, easier to navigate.
Plus, I have heard about it pretty much everywhere. It is commonly compared to Threads. I only know and heard about Mastodon on Lemmy.