I need to follow specific users on Mastodon to tailor my experience. On Lemmy, I follow entire communities where people can engage, all grouped by posts. It feels way less chaotic.
I know I could follow tags on Mastodon, but IMO their discoverability is even worse than communities, and if someone decides to spam a tag with irrelevant content there's not much I can do but to block the account.
With communities, there's at least some moderation happening.
But then maybe it's my own bias, I always preferred interacting on Reddit vs Twitter.