Windows on arm was a thing, I had a surface 2 rt about a decade ago, too bad it never felt like microsoft ever really fully committed to the idea imo, and yeah x86 apps wouldn't run on it (though there was an emulation tool apparently, was community developed). Market was definitely there (though I'm not sure how big it was, probably a cross over with netbook users), they just fumbled it like they did windows phone in my view.