RCS is an international standard. Google only adds their client (and running the service if your mobile provider doesn't).
Don't know what EU apps are you talking about, but yes, mobile apps need Google services. Web interfaces don't.
Don't know what EU apps are you talking about, but yes, mobile apps need Google services. Web interfaces don't.
Pretty much all banking apps for Android won't work without Google Play Services, so once again if you are using Lineage or Graphene, you are still stuck with US company to use your European banking services on the phone.
Nice red herring. The number of implementations is irrelevant here, although Wikipedia says Samsung had one too.
Here's the standard, try Ctrl+F "Google": https://www.gsma.com/solutions-and-impact/technologies/netwo...
nobody cares about standards, if they are pretty much monopolized by one comapny