The real question that I rarely see answered about all of these hand-held PCs coming out is, can they cleanly suspend and resume at any point during gameplay without causing problems? That's (IMO) the single most important feature of the Steam Deck and one I've never seen work as well in other hand held PCs.
Probably because that's a feature of whatever OS you run on it. If you stick to Windows that most likely comes with it, then no. But if you install something like ChimeraOS, then it should work.
It's a rather standard feature. Hardware and software have to be built/configured right for it to work well. That's what Valve did. I don't think there is any special sauce involved software wise.