I have a Series X and a Steamdeck. Tbh I don’t play the latter that much compared to the Xbox. But I got the Steamdeck mainly for emulation which it is v good for. I got the cheapest model in a Steam sale and upgraded the internal drive which is pretty easy to do. With Steam OS you can play Xbox games via Xcloud or create a windows boot drive and play pc Gamepass game native if you want. Steam games are always on sale and are cheaper anyway most of the time compared to console equivalents or look at Humble bundles to create a quick library of games. I find the turn base, puzzle or SP games easier on the deck due to the screen size. Something like Vampire Survivours is a perfect fit.