I have to admit, I like the smaller community size here. There's more real conversation going on. The downside to mass migration is that that is put at risk.
That said a federated platform has an advantage here. It allows for niche communities to thrive in a way that I think was harder on centralized platforms like Reddit.
The web is federated in theory but that does not stop the larger companies from monopolizing the traffic. Think of Reddit, Google, etc. as a federated instance of the WWW.