I joined Lemmy very recently and the concept of the different federated servers was easily my biggest stumbling block in signing up.
At a glance, it’s really hard to tell what choosing a server represents. Even now, I’m pretty fuzzy on it and could barely explain it to my partner.
Even after getting a rough idea of how the federated server concept works, it’s not easy to know which server has the right vibe/ content for you.
This, to me, is the biggest cause of congregating on the larger servers. Without a resource that can easily explain the differences between each server (and why it matters), it requires more effort than the average person is willing to expend to choose a non-“default” server.