Q. Is this really as harmful as you think?
A. Go to your parents house, your grandparents house etc and look at their Windows PC, look at the installed software in the past year, and try to use the device. Run some antivirus scans. There’s no way this implementation doesn’t end in tears — there’s a reason there’s a trillion dollar security industry, and that most problems revolve around malware and endpoints.
Most compromises live in user space. Locking down the kernel is great and all but “most attacks” are running as the logged in user doing operations that user is permitted to do.
Even on userland stuff Apple controls tightly. If they want to require a user to manually click, they will get that. If they want it to be a physical mouse and keyboard doing it, they will get that too. They own the device, and have complete control, not the user or “owner”.