I’m kinda split on it tbh.
On one hand, we have a literal ip spacing crisis - mainly because there’s bajillions of arguably repetitive content among other non scrupulous stuff.
On the other hand, having a niche community has its pros.
Totally agree with your analogy of Walmart though - but then there’s also things like FediNet which basically let people use a standard framework to hve their niches.
It’ll be interesting to see what the future brings