IMO, the likely cause is AMD capitalizing on multiple OEMs having Steam-Deck envy and/or setting the foundation for the Steam Deck 2 with near-desktop graphics fidelity rather than 800p medium/low settings users have to put up with.

Way too power hungry for a handheld gaming machine and way too small market. No way AMD spent all this effort designing a brand new SoC architecture just for Steam Deck.