I think something will change or evolve. It's very popular with a lot of people, so has got most things right.Yep, multiple accounts is not the answer, I think you are right.
In the final analysis the idea of decentralisation is - well, lack of centralisation and that is the greatest benefit. Perhaps that is the only real benefit.
I wonder whether eventually most users would clump up into just a handful of servers based on moderation policies, as you suggest.
It's just the issue of being in one community and a sense of guilt when you post something totally unrelated, or despising your fellow community members for filling the local feed with jokes etc!