Public Windows Phone 7, 8, and Windows Mobile 10 devices were all arm. Intel cancelled further development on Atom for phones at roughly the same time Microsoft announced Windows Mobile 10's desktop convergence feature (plug phone into monitor and get a desktop-like experience, I think there was a wireless option as well). It's pretty simple to speculate this would have been way more nifty on an x86 chip, because Windows Mobile 10 was more or less Windows 10, so you would have a bigger software library, instead of only UWP applications.

Commercially made x86 Android phones exist, the most popular to my knowledge were some of the Asus ZenPhone models.