>fused location system ... which can't exist without Googles involvement

That's kind of a cop-out though. It certainly could exist without Google's involvement if the location provider were a pluggable module within AOSP. microG does this - my phone supports the fused location API using Mozilla's location database instead of Google's. (There are other modules too, like a local database of cell towers if you're willing to dedicate some storage to it.)

Push notifications and Google login sure, but some of what's in the Play Services APIs should really be in AOSP, IMO.

EDIT: For that matter, you could even have the push provider available as a module too, even though Google's push service is the only one currently available.

How would you have push provider available as a module? The sender is communicating with a particular push provider.

The client could provide the push service to use when initially setting up push notifications for that app. I believe that's how Web Push works.

Sure and you can use microG and other services on your Google free phone. I do agree that flashing firmware without Google services should be easier on devices, but the actors preventing that aren't Google (locked bootloaders are demanded by your American telcos like Verizon, DRM lockdown is demanded by the copyright lobby and SoC vendors refuse to release the kernel sources).

But in general, I don't get what your expectation is, that Google will spend millions developing an OS and then give it to competition or deliberately provide worse user experience than their main competitor?