Basically I see Lemmy like my current Linux distro
This is also a really good thing. The only problem I see is that it's a little more complicated if sites would change their backend.
Like, imagine in 10 years Lemmy isn't the hottest threadiverse backend any more and now it's something else. But what about the existing sites? It's infeasible for all users to manually migrate their accounts to other, newer instances and they might not want to either (they might like their current instance).
So given that situation, instances need a migration path to a newer backend. But that seems more complicated than switching a Linux distro for as a single individual.