I understand wanting to play an old game, but why would you want to jump through hoops to run it on old hardware?
It's just a feel that some nostalgic collectors have: they want to handle the real hardware thing to put together with the software. (yes, I know it sounds naughty; no, I won't take it back)
People "justify" Valve, I don't think there's need for that (justify a big corpo, I mean); Valve don't want to deal with the hardware business side of repairing stuff; yeah, it's their right to do so: but this also tell us Valve isn't mature enough as hardware company, and you can't expect them to mature in this direction if they (also) don't get serious into providing affordable repair service.
This tells me: Steam Deck 2? Maybe... Steam Deck 3? Unlikely. They will push for an "alternative OS".. and will lose for lack of focus (Microsoft can easily kick them out with the Windows industrial's weight). As far I can see, they are not committed to hardware, no other OEM will do this for them.
(Look at how Google has been consistent with their 'Google Phone' throughout the entire history of Android: they know it’s foolish to rely only on 'OEM goodwill' and stop there. Google Pixel devices were better than Windows Mobile and the 'DualBoot' Android/Windows... that’s how Google beat Microsoft in the race)