Larian is having trouble fitting Baldur’s Gate III on the Xbox Series S, the lower-priced and lower-powered console in Microsoft’s ninth-generation lineup.
I was looking up more information on why there’s such an issue getting BG3 on Xbox, and found this article with a lot more detail on the topic.
EDIT: The issue isn’t graphics or frame rate; it’s memory. The article goes into detail.
A console is a closed off system. The Deck is literally just a Linux PC in handheld format. You can do everything with it, Valve even explicitly encourages you to do that.