My dream Linux gaming setup would be a fully configured isolated container that can be run on any host OS. Games are the prime candidates for containerization because they're all proprietary, and there's absolutely no reason a game needs user level permissions or to interact with any other program on the system.
Imagine if you could just pull the OGC container from a public registry on your distro of choice, run your game, and then just shut it down when you're done.
I suspect the biggest barrier would be sufficiently low overhead GPU access though.