Interesting to think about how many pieces are almost in place for this. The two big players in game engines have had a huge iOS presence for years, just for a different segment of the gaming market; PC game developers have had a few years now to optimize titles for the constraints of the Steam Deck; Apple's game porting toolkit was just announced this past WWDC…

If Valve gets the opportunity to gain a foothold on iOS, the landscape could change very quickly.