I think both things can be simultaneously true. There are a million sub-cultures that can now exist, that are no longer tied to a geographic location. This is both good and bad. Good, insofar as if you're in the middle of Ohio in a 2000 person town, and really-really into model trains or whatever, you can find an online community that shares this. But I also think it's bad insofar as we've lost some sense of culture or commonality with our (geographic) neighbors.

But to the homogenization point; I still think within a specific sub-culture (sewing circles), you can have global homogenization. The sewing circle might new be global, on facebook and tiktok, instead of 10,000 insular hamlets. Is this bad/good? I'm not sure. There's nothing from stopping you creating a local facebook group. And in theory, good ideas can spread rather than be confined to a specific geographic group. But I can't help feeling that some independent thought and ways of thinking are lost through this globalization.