I’ve been using the Steamdeck with Xreal glasses (1080p 60hz) since the release and can confirm the AMD 13 with Nreal glasses is a solid upgrade. I was getting MUCH BETTER graphics and frame rates while playing Warhammer: darktides, or Cyberpunk 2077.
You’d be better off comparing with something like a Lenovo Legion Go or Asus ROG Ally as both of these use an APU (do AMD still use that phrase?) that most closely approximates the 7840U (compare Z1 Extreme) or 7640U (compare Z1).
If you want a handheld, you could theoretically buy an AMD Framework board and go the DIY handheld route but they’ve only used an Intel board so far, so YMMV.
Then again, you can dock a Legion Go or ROG Ally and essentially get a similarly-performing system to a Framework AMD laptop with a keyboard and screen.
Ultimately, what form factor do you want? The whole point of Framework is the sustainability / noodleability of the platform so if that’s what you’re after, go Framework.
If you want to play handheld games with AMD 7x40U-ish performance, get a Go or Ally.