Steam Deck

You realize this’ll occur at the expense of Microsoft treating the user as an untrustworthy enemy.

What do you mean? Take away your ability to create drivers? Because it's already extremely limited and you need to get signed. I guess this "change" would just mean not signing any new antivirus drivers.

This means modding (even for offline play) will not be allowed. Heck, even modify ini files might be viewed as “hacking”.

That's a completely wrong take. Whether or not an anticheat runs in the kernel or not does not mean people can just go and edit their files. Even with a kernel level anticheat people can already do that if the driver is not running. The correct way is to do purity checks during connection to an online server, and only allow serverside code to update the gamestate. Any texture file hacks and local purity bypasses for those would need to be caught by the userland anticheat, like it has been done for ages. Not the best solution, but far more privacy friendly.

I agree removing the need for anti-cheat in principal sounds nice, but this means archiving games or porting them to “unsupported platforms” will be relics of the past.

Another weird take. Are you talking about the anticheat not being installable anymore? Because even if a game comes with a kernel level anticheat it would need a valid certificate, so any dead game would eventually have this problem regardless of it being allowed to install the driver. Porting games would in almost all cases get rid of the anticheat or somehow null it, disable any custom servers from forcing a valid anticheat, stuff like that. And archiving would be much easier without any anticheat at all, again regardless of kernel anticheat or userland anticheat.

MUCH better solutions against hacker are to use all this amazing machine learning stuff on the server side, put more power back into the hands of admins and their selfhosted servers, and handle reports about hackers better and faster.