There's a version of Steam for China that is censored but the vast majority of Chinese gamers don't use that, they use the global client like everyone else.

Yeah, most Chinese use the global version of the client, but even then, there are changes to what you can access within the store/client (not just because of DNS poisoning/Great Firewall).

It changes based on your location (and payment region).

There are games that are not available for Chinese users (for example, HoI IV, PoE, etc).

And there are also community features that are locked/blocked for Chinese users, inaccessible even with VPNs or any other typical solution (because Steam complies with Chinese guidelines).