There are a lot of assumptions to unpack in that and this may not be the right place for it, but I’m not convinced that centralizing servers implies locking down the culture of the space. Or, perhaps more accurately, that having multiple servers does anything to prevent the culture from consolidating. I don’t think Fedi gets accused of being particularly culturally diverse, honestly.

I think it prevents that culture from being built from the top down (or overmonetized from the top down) through unpopular or unilateral choices. That’s a thing. But becoming less culturally unified? Haven’t seen evidence about it.

I do get that people believe that. They’ll spend ages arguing about what service or instance to join and whatnot. The end result tends to be fairly similar. I’ll say that the main differences are dictated by design, rather than intent or moderation, and that’s been an interesting thing to see play out.