They tried that method with the steam machines, it didnt work. A bunch of companies put out half arsed cash in versions and it went nowhere. By putting Valve’s whole weight behind one platform that they tested extensively they got a great product that has made waves. Opening it up now that it has momentum makes sense, but they absolutely made the right call making the steam deck the focus rather than making it hardware agnostic.
What do you use as a vm on an arm mac? I was looking into this a while back to run linux on my work m3 macbook but i couldnt find any good options