(Update: Qualcomm has responded) Intel co-CEO Michelle Johnston has asserted that Snapdragon-powered laptops are affected by high return rates. Although there is an absence of hard data on the matter, it is hard to deny that ARM-based Windows PCs have a long way to go before being considered a match for the market dominance by x86.
Translating syscalls and translating opcodes (especially efficiently) are different things.
And we don’t.
But yes, this is possible and Windows for ARM includes such a translation layer. Except it’s not very good yet.
In some sense ARM everywhere is a nightmare. There’s no standard like EFI or OpenFirmware for ARM PCs.
I hope that changes.