Well if you are interested in more depth, let me just copy and paste myself from Reddit.

Federated social media still exists, and it's perfectly functional. It comes in three forms: Lemmy (Lemmy.world here), Piefed (Piefed.social), and Mbin (Fedia.io). All of the different softwares have different UIs and tools that may appeal to different people. I've linked the largest, 'generalist' instances of each particular software for people who are curious to join. They all can network together regardless of which one you choose to join.

For all those who don't understand "federated" social media (I've seen people not quite get it in the comments in prior discussions) - it's basically like if there were hundreds of different reddit-type websites but all federated together. Users on one particular reddit site can interact with users and communities on the other sites, provided they are federated together. The entire point of the system is that there is no single owner. An instance that goes bad, only makes itself go bad. Any user that does not like the policy of a particular site can just go elsewhere and an especially badly run, toxic instance will find itself completely blocked by other instances - left in the wilderness (reactionary, right-wing instances that formed are completely isolated with no-one that links up to them). So in lemmy terms, most users land on Lemmy.world. It's the largest instance. However, if you don't like how the management of that place run the instance - you can move to Lemmy.zip or sh.itjust.works or wherever else.

It's also quite cool too beyond that because it there are themed instances. There's instances focused on specific countries (lemmy.ca/piefed.ca, feddit.uk, aussie.zone etc). There's instances for particular topics (programming.dev, mander.xyz (science), ani.social) - so there's a real potential for diverse instances for people to join focused to their interests. There's also language-based instances - I know of a German-based one and a Portuguese based one.

It's much smaller than Reddit obviously, but no other reddit-alternative has come anywhere close to the activity of the Threadiverse. It isn't perfect, it'll never be perfect - but it's the most built-up and active alternative that exists, and because it's smaller across-the-board, there's actual opportunity for users to have some input in shaping the culture of it via the communities they make (a note here is also that badly-run communities on a particular instance can also be abandoned and remade elsewhere - there's no ability to capture a name and squat on it on the Threadiverse on the basis that there's dozens of other viable instances where the same community can be made, and better-run elsewhere). This is actually a pretty good thing.

For example of federation, we're both on piefed.social - but if you look at this community - you can see it comes from piefed.zip. Newcomers@piefed.zip. But because piefed.zip is federated with piefed.social, we can interact on it.