I thought this was well-known, Android is not private at all until you degoogle. Unlock your bootloader then install a ROM without Google Play Services such as GrapheneOS, CalyxOS or LineageOS.
You can consider installing microG also as an open-source minimal implementation of Google Play Services if some of it's functionality is absolutely necessary for you to keep.
You can consider installing microG also as an open-source minimal implementation of Google Play Services if some of it's functionality is absolutely necessary for you to keep.