Moguri mod works great on the Steam deck. It’s a bit of a learning curve to get it installed, but there’s a guide that will take you through the entire process, and it will teach you some about the more niche features of the deck.
The problem is the Series S sold a lot, last I read it was about two thirds of their user base. Microsoft also want to push platform independence using X Cloud, which solves their Series S issues, but with the feature parity requirement in the Series X and S, they keep hitting this issue.