I briefly tried mastadon. I don't like the format, it's a twitter basically, the federation is a plus, but the entire thing is a popularity contest. Almost all engagement is driven by those with large follower counts, 99 percent of posts are seen by almost no one.

Which is ok if you want to build a following, but for your everyday user, reddit or lemmy is more egalitarian, your posts, and your comments, can be considered on their own merit regardless of your follower count.