Did I say it did? Maybe I worded it wrong but I meant that you need to use (and install it) to use the vast majority of apps, and it's deeply integrated, in the play store and apps.. and affects many parts of android
If you do install it, which you probably will unless you're okay with living 10 years in the past and losing time, then you're pretty much back to square one
Be my guest, uninstall GPServices and see. It's known that all mainstream apps require it. Things like youtube obviously, and all google apps, uber, lyft, reddit, bank apps, discord (unsure), mcdonalds, burger king, yuka... many smaller apps and many games as well. If they work by luck, then you likely won't have notifications. There's no easy database for this and you probably know it
Then, for the privacy points, then you also know google's privacy policy. Google play services is closed source, so yea, good luck finding proof for this, just like for apple
where? Criticizing something specific inherently implies there is a better alternative, or you wouldn't be focused specifically on apple. I'm saying android is not and AOSP is not viable due to being an outdated user experience and supporting much much less apps and features, as well as not really being used without play services