For Microblogging so far I’ve used Mastodon because it seems to have the most feature complete apps from what I’ve seen (Megalodon and Tusky are both good). For the most part they interface together, I follow people on Misskey.
While it’s got a good amount of activity I don’t use it as much as Lemmy since the advantage here is that things are sorted into communities so it’s easier to find good content. You can follow tags on Mastodon, but because it has no real algorithm and the “toots” are less substantial than Lemmy submissions I find that you get a lot of banal status updates. It also has to compete with Bluesky which has more name recognition being made by ex-Twitterites that also draws more users away from it. If you can find good people to follow it’s good but I think we’re still waiting on a critical mass of people to move from the former site.