Valve? MS will compete that way indirectly. I snagged a SteamDeck - I haven't played games this much in a long time. Since getting it I've played through a bunch of triple A games (God of War, replayed the mass effect trilogy, etc), and a whole host of Nintendo exclusives via emulation.
The fact that Nintendo lawyers are working overtime taking down youtube SteamDeck videos that barely even mention emulation feels like an admission that they know the steamdeck is a threat. They sure didn't seem to work as hard to take down videos showing emulation for other platforms like the Aya Neo.