.. and construe terms in the worst possible double-speak way: purchase means rental, off means "spy on you mode", ...?

Except more and more options are being taken away by Google, so there's no menu (not even developer setting?!?) that could give you any sense of freedom back. For examples (not all privacy-related), see clipboard permissions, background usage rules, Firebase notifications, WiFi scanning...

The only way to get freedom back on Android is to either run a very old version (bad!) or undo all the bad changes in an AOSP fork (difficult).