I can’t claim to know what the designers intended, but having users spread across a large numbers of servers is terribly inefficient for how Lemmy works: each server maintains a copy of each community that it’s users are subscribed to, and changes to those communities need to be communicated across each of those instances.

Given this architecture, it is much more efficient and robust to have users concentrate on what are effectively high performance cacheing servers, and communities spread out on smaller, interest focused instances.