Valve have confirmed that SteamOS support for non-Steam Deck handhelds is ticking along - unlike dual booting, which will elude Deck owners a while longer.
i get we're on lemmy so this sentiment might be amplified, but just a reminder that most
people unfortunately do not give a shit about this sort of thing
I think the hard part with using the os from a playstation or switch instead of an emulator would be getting the hardware running with drivers and whatnot. While it may be possible I can't see it as very practical unless you are that kind of coding nerd and you want to do it as a challenge.