It also doesn't prevent people from using VPNs: the apps are just a convenient interface, Apple hasn't removed the ability to manually add your own.

More importantly, China is planning to block VPN at the protocol level starting in February. Apple can't do anything about that, and if all the other reasons against taking a stand here didn't make sense on their own, consider how silly it'd be to take a stand for a technology that's about to stop working anyway.