It's actually pretty simple, they've inadvertently self segregated.

So the dudes who maintain the code for Lemmy, which is a framework that most of these instances are built off of, are what we call "Tankies" because they support the Chinese dictatorship, Russia's invasion of Ukraine, etc. They're the "Communists" with emphasis on the quotation marks, so to speak. They oppose "Capitalist" countries which are any western nation that stands in the way of expansion. They oppose "Liberals" as they claim it's a "Capitalist" ideology but actually because it's the ideology of promoting human rights which conflict with their ideal form of government.

Now, I mentioned those dudes maintain the code, they also maintain the landing page where a lot of people are first exposed to a list of lemmy servers to pick from. Other frameworks are being developed right now so we can move away from Lemmy, such as Piefed which is the backbone for Piefed.social and Piefed.world but they're still missing a couple of features.

For example the instance you and me are on, Lemmy.world , is also run by Piefed.world hosts but the lemmy.world allows attaching images to comments while Piefed.world lacks that functionality as of yet, though they did recently update to a new version. Our instance is one of many defederated from Hexbear and Stalingrad, which are the same Tankies as ML but with the masks off, they unapologetically promote Xi Jinping and Putin, so those users cannot interact with our posts or comments at all, but it still remains federated with Lemmy.ml sadly as that's the lemmy instance where news about the framework and updates come from.

The reason why all of this is happening is because somebody is paying for it. Some lonely internet users in the west are funding a place to go, while some military regimes are funding it because it's a psyop made to promote their goals and create radical infighting in the west. The fediverse is everything great about other social medias with less of the cons except for the fact that we completely lack the ability to defend it from hostile actors in ways that a large corporation with unlimited resources and centralized detection algorithms could (if they even would).