So, you read “we already have these surveillance capability” and you’re fine with it? Interesting.
The whole point of “user mode” is that it is possible to separate things. Even on Windows, assuming proper handling of your storage and settings, one account can be barred from accessing another account data it should not have access to. Granted, most people won’t care, but you can do it, and run separate windows accounts for games and personal stuff for example. You can even do it without constantly switching between them.
Not only kernel mode “anticheat” will allow snooping on the current account, but on others too, that’s the key difference here. As a user/customer, it removes the possibility of having private stuff on your computer at all.