In 2017, Windows on ARM was pretty bad, Windows RT not Windows 10 that had been released for x86 in 2015. I know RT started with only support for Store apps, but I don't know when it allowed native apps. x86 emulation wasn't present in RT either.

Today? Sure, they could probably sell some arm cpus; in 2017, doesn't seem likely.

Do the typical windows user run only Microsoft Apps?

I think you can get 95% of compatibility but the 5% of apps not running, even though they might be used once every full moon and there are alternatives, might be seen as a major blocker for a potential customer if he can still buy another computer with 100% compatibility.