I think what Valve achieved is amazing, but we're nowhere near major publishers targeting Linux as SOP. That means that if Valve loses interest in the Steam Deck you're probably going to see game compatibility for newer titles start to degrade.

I think there's kind of an ironic downside to Valve's approach as well. Proton is so good that there's little incentive for developers to support Linux natively - they can just target Windows and rely on Valve to fix it.

Still, this is the best that Linux gaming has been in my lifetime.