As far as I can tell from my venture into Mastodon’s feeds, the demographics of that part of Fediverse isn’t that different from what Lemmy has: the same political takes, FOSS stuff, “big corpos bad”, etc.
I wonder, is there anything that Mastodon excels at that Lemmy just doesn’t provide? For example, I noticed that there are game developers and artists posting their stuff on Mastodon. Not many game developers (or any creatives, really) on Lemmy though.
I can contribute posts to Mastodon by adding hashtags to my posts, and I can already follow users from there to see their posts (ahhh toots?) even if they aren’t bound to any community. So, at least on Piefed, the situation is improving bit by bit.