Have you read Apple’s Platform Security Guide?
https://support.apple.com/guide/security/welcome/web
It’s extremely useful and fairly detailed, but the reason I bring it up is that I think it shows just how mind-bogglingly complex security systems are. I just can’t believe that 99% of Apple users would be able to understand even the Platform Security Guide, much less be able to evaluate what’s happening on an Apple device at an extremely low level (and interested enough to bother).
If you don’t trust Apple, you shouldn’t buy Apple devices, and the same goes for Google and Microsoft and Amazon. The best operating system for someone who doesn’t trust anyone is probably some flavor of Linux.