Problem is that Valve have yet to ever go to V2 for their hardware unfortunately.
Thankfully, I've only heard good things about the steam deck, so hopefully they'll fix whatever hardware/manufacturing problems they might find and make changes to make it better.
Barring that, I hear it's popular enough that there will probably be third party "equivalent" hardware soon, and maybe they would see it as profitable enough to iterate and make better if valve for some reason doesn't.