Android would be dead in the water today if it wasn't for Play Services. Developing for Android is still painful today because but Play Services at least meant that you could expect a certain range of features spanning multiple major releases of Android.

I'm pretty sure that Play Services wasn't something Google really wanted to have but were forced to implement because so many OEMs just shit the bed w/r/t their Android forks.

Only because they didn't licensed Android in a way that would have prevented that in first place, nor have proper clauses on their Play Store contracts.

Yes, although at least both Android and Fuchsia are released under genuinely open source licenses, even if they development model isn't open.

These licenses are totally meaningless when Google make anti-competitive threats to their partners for attempting to exercise that license. They benefit from all the marketing of their vendor ecosystem in the public eye using the open thing, while quietly holding a gun to everyone's head in the background. That is the absolute antithesis of what "genuine open source" is supposed to be about, it is a marketing ruse and you've fallen for it.

I have a Pixel phone and run GrapheneOS on it. No Play Services, no Google apps, only open source software from F-Droid. Works really well.

That is because you are clearly a Computer person. The average person has their entire digital life owned by Google.

My point is that it's totally possible to have an Android phone without any proprietary Google software components, thanks to Android being open source.

Same with Fuchsia - its license should allow to make a fully FOSS privacy-respecting variant, and maybe it would be something I could recommend to my friends or family to replace Windows on their desktop for example (if Fuchsia becomes popular enough). At least such option exists, unlike in the case of Windows, so I don't see Fuchsia as a bad thing.

Good luck with Android 12, ART is now also part of GSI images and delivery over Play Store.

I'm not familiar enough with Android internals, but as I understood from a quick research this means that it will be possible now to upgrade the Android Runtime through the Play Store (which was handled by phone manufacturers?). Is it a problem for distributions without the Play Store like GrapheneOS or LineageOS? Why?

Depends how they manage to have Play Services running on them.

https://source.android.com/devices/architecture/modular-syst...

The information on the link is outdated, it was presented at Google IO that Android 12 will now also ship ART as APEX module.

Most likely by then the AOSP documentation will be accordingly updated.