It's a little like comparing a top of the line gaming laptop to a middle of the road efficient laptop. Sure the games will run a bit better on the powerful laptop, but you're trading that for battery life. The Steam Deck is insanely efficient, and they made a few hard tradeoffs like the 1280x800 display resolution (which is great for battery, and honestly plenty sharp for the screen size).
I'm still a little blown away it runs Balder's Gate 3 and Cyberlunk 2077 at all.