What if it turned out that ease of use and OS-wide app consistency was the easy part all along? That building good APIs - which includes not changing them, making a good publishing experience - which includes not changing your rules every six months, and making your developers rich - which includes lowering fees - were the hard parts?
Besides the average person does care about privacy and security. Keychain is a product everyone on macOS and iOS uses. Imagine if the OS forced Private Browsing to actually work.