So yes, if I’m willing to go to China and use Chinese OEM customized phones with Chinese apps, I will be golden…

You're free to use the same Android that the Chinese OEMs (and Amazon) built their phones on yourself, without traveling to China. It's true that a reasonable definition of "no one" wanted Amazon's phones, but a much more lenient definition has to be used for the Chinese OEMs.

And in any other country besides China, how many of the apps that most people use don’t have a dependency on Google Play Services APIs?

Google has been moving much of what a western user considers “Android” out of the AOSP code since 2013.

No APIs have been moved out of AOSP. Google Play Services is itself built on top of AOSP. If you mean they removed the email client, that's because there are now other open source email clients that are much better.

These are the APIs that are part of Google Play Services

https://en.wikipedia.org/wiki/Google_Play_Services