This isn't a problem unique to what we're talking about, virtually every desktop PC on the planet has proprietary blobs running regardless of the OS used. I agree it sucks, but they're also not strictly necessary to run the containerized setup I proposed (any more than they're necessary to run the computer itself). It's possible to have attestation without anything proprietary/closed source.

While it's possible to have attestation without anything proprietary/closed source. If you look at widevine you will quickly notice how that's very unlikely to happen. While it's possible to do this in containers, if you look at how DRM is built into the HDMI protocol, you will notice that it's unlikely you'll ever get to control a base while running the proprietary stuff in a container.

Your idea is somewhat possible, but it's never going to happen in reality. I can already run windows in a VM for the exact same result.

It's unlikely sure, but I look at the alternatives and they seem even less likely. I really doubt consumers would be happy with normalizing rootkits on Linux, even those at Valve wouldn't want that. So what other choices are there? That question left me with the answer I gave.

Running Windows in a VM would be less efficient than running a stripped down Linux stack inside of a container. Going the Linux+Wine route requires less proprietary code and would be free to license. Hardly an exact same result.

There just won't be any rootkits or games which require such anti cheat on linux. That's the most likely end result.

There already are games with anti-cheat on Linux, they're just using (arguably) less effective versions of them.

Valve are financially incentivized to get as many games working as possible, I don't think it makes sense for them to do nothing at all about this. They have a head start now due to the general crappiness of Windows on a handheld but Microsoft's mobile offerings could catch up and given that would have Call of Duty among a lot of other heavy hitters available while Deck wouldn't, that is a problem that Valve would need to solve in order to not get stomped.