I'm on Mastodon, Twitter, Threads and Bluesky and, FWIW, Mastodon is the worst and the one with the most potential. Worst, for so many things, 100 tiny points of friction for little return; culture feels very much like eating your vegetables; so many overly earnest and humorless people.
re your arseholes comment - this is the main way Mastodon is actively unsafe for minority communities. The insufferable 'moral superiority' airs is exactly why people don't want to make the move to Mastodon. Ironically Mastodon could have offered a viable new home to a pretty vast network of folks but chose the hugbox model instead. I'm across a few Mastodon's and it just depressing the amount of people actively shutting down people sharing (through admin bans or active brigading [the lgbt user shutting down a cryptography professor in a technical discussion for 'word violence' was chef's kiss]) and telling them to hide their trauma behind content warnings. It just sucks. And every Mastodon user confronted by this is told: "well move to another server": its wrong and its not how community works.
But Federation is the right model, in the long run. Which is why Threads will federate, they can't take the chance and had to bake it in at the beginning. I think they need to figure out an architecture for better moderation but that will take years.