Honestly Valve needs to have a policy for this. If a game that once worked on Steamdeck and now no longer works after publisher intervention then refunds need to be issued. I have BF2042, BFV and BF1 and 1 was the LAST one I could still play on Linux. Now I have 3 digital paperweights that I can't play anymore. I want my money back.
It doesn't just do nothing. They know for sure it does nothing, is not theoretically capable of doing more than nothing to prevent cheating, and that it is a giant security hole.
They just don't care, because it lets them install a rootkit on your computer.