The answer to that is Windows proper either ran on top of DOS or ran a DOS-compatible layer (Wow32). Windows Mobile 1.0-6.x and Windows Phone 7.x were based on

The answer to that is Windows proper either ran on top of DOS or ran a DOS-compatible layer (Wow32). Windows Mobile 1.0-6.x and Windows Phone 7.x were based on the Windows CE (an embedded OS from the 90s) where as Windows Phone 8.x and Windows 10 Mobile were NT based with modifications made for ARM and battery life. Different kernels are the reason for the breakage.