www.techpowerup.com/…/xbox-series-s-gpu.c3683

www.techpowerup.com/…/steam-deck-gpu.c3897

The Series S is a much faster machine. Larger GPU, faster memory, double the CPU cores, higher clocks it can keep at full speed more frequently; it’s really no contest.

Not to say the Deck is bad by any means.

But if you were to sell it, and you are worried about fidelity, I’d save up until you are ready to immediately trade it for a Steam Machine.