Noob Question: If you aren't willing to deal with custom OSes like Linux (for computers) and Android Custom Roms (for phones), do you just not have any privacy at all?
I mean, exactly how invasive are default operating systems? (Like Windows, Mac, Chrome OS, Android, iOS) Do they log your keystrokes, log passwords, capture screen, upload your photos, videos, or audio? (Assuming you aren't a target of government) Is it even possible for the average person who doesn't feel comfortable messing with installing operating systems to have any privacy?
Windows 10 & 11 indeed do log your keystrokes, browsing history, etc. by default, according to the T&C - also the Microsoft swiftkey keyboard for Android does as well.
Here is a good guide for making Windows a little more private, although there really is no escaping at least basic telemetry, which is still way too revealing in my opinion: