So there's a catch 22 here. ARM was niche on desktop because no-one made the first move. That is, until Apple launched the M1, which is exactly the failure of imagination of Microsoft that GP is talking about. Though a quick google shows they did indeed investigate this avenue in 2016 for Windows 10, though they obviously didn't commit to it:
> On December 7, 2016, Microsoft announced that, as part of a partnership with Qualcomm, it planned to introduce support for running Win32 software on ARM architecture with a 32-bit x86 processor emulator, in 2017. Terry Myerson stated that this move would enable the production of Qualcomm Snapdragon-based Windows devices with cellular connectivity and improved power efficiency over Intel-compatible devices, and still capable of running the majority of existing Windows software (unlike the previous Windows RT, which was restricted to Windows Store apps). Microsoft is initially targeting this project towards laptops.
To show them that their battery life could go from 2.5 hours to 8 or more, perhaps. That was the Mac experience that customers weren't asking for yet "wowed" them when it came.
they definitely were asking for longer battery life and cooling systems less noisy than a fighter jet, but the supply side of the market was a desert filled with minefields and duds until the M1.
ARM tends to have better performance per watt, leading to improved battery life and thinner/lighter devices at the same performance and price point. Are you sure nobody is asking for it?
Correction, ARM chips tend to be designed for better performance per watt. The instruction set has nothing to do with it. For a long time intel and amd neglected the mobile markets. That is about to change.
Even now ARM is niche.