In the past, I’ve heard about how Google can keep records of all your Google phone’s past locations and text messages.
What about RCS messages which supposedly are encrypted from Android to Android? I know that it’s possible that they secretly keep a log behind the scenes, but as far as the regular consumer knows is there any record being kept with regard to the contents of these RCS messages?
If you login with Google on your phone with an OS made by Google then you can expect ALL the content on that phone to be potentially at least processed by that company which might including sending back data in some form.
That’s not just Google or Microsoft, it’s any operating system. The OS can see everything you can see and more. If you do not trust the maker of the OS then you have a problem that no application ran by that OS can solve. encryption in all its forms, e.g. encrypted disk, E2EE or homomorphic encryption do not matter if you are on an “end” (e.g. your phone or desktop) that you do not trust.