USA : Air Conditioners : EU
China : ??? : USA

i.e what are there technologies that are taken for granted, widespread, and non controversial in China that aren't as widely adopted in the US

QR Codes is my best comparison

They’re everywhere in China and used for everything, in the US they have niche use cases

Since everything on this planet is produced in China and since the Chinese from the moment they produce it can make direct use of it in their own country, it is not possible to identify a technology/product X that is not already part of the homologation.