AllyX/LegionGo/windows based

Pros:
- Most games would be compatible
- Familiarity with windows

Cons:
- Navigation kinda sucks with controller for the OS afaik since it's windows
- The drivers are vendor locked, so like AllyX, if amd updates anything, have to wait for asus to push the update through their buggy armory crate

Steamdeck

Pros:
- Great ui with good navigation using the controls
- Sleep mode/suspend-resume to pause game mid-play, kinda like psp/vita/3ds
- Can try different runtimes to maximize performance, although kinda leceh

Cons:
- Not all games will be compatible, especially competitive games with anticheat
- Not as powderful as other windows based machines

Compromise
Buy AllyX/LegionGo/etc and install BazziteOS or wait for steamOS to release for those devices, install as dualboot to get the best of both worlds