If you’re sandboxing Google play services, you are, by definition, still installing play services. They are still running, but are sandboxed. So I don’t see how you see any less battery drain.
I run MicroG instead of the proprietary Google play services, and while I do see a bit ofl an increase in battery life for light usage, for medium and heavy usage it’s pretty much the same. Admittedly my battery is pretty old.
Because you can add only what you want and restrict notification and other data transfer, auto turn off when not in use, etc. It is the constant google chit chat that kills battery. My play app keeps nagging it wants more permission to function better but I just deny it. also it is just play service, no gmail, no google drive, etc. and I didn’t have it snooze power this week but only 3% play aervice use since sundays charge.
By being ripped out and sandboxed the same way other apps are, Google services isn’t free to siphon battery. This means you can restrict battery use and cut the constant communication down. Thus saving battery. If you allow it, yes it is not different than if it was preloaded.
