Drivers for hardware, games and apps will only work if they’re designed for a Windows 10 ARM-based PC.
64-bit (x64) apps won’t work. You’ll need 64-bit (ARM64) apps, 32-bit (ARM32) apps, or 32-bit (x86) apps.
Certain games won’t work. Games and apps won’t work if they use a version of OpenGL greater than 1.1.
Apps that customize the Windows experience might have problems. This includes some input method editors (IMEs), assistive technologies, and cloud storage apps.
Some third-party antivirus software can’t be installed.
Windows Fax and Scan isn’t available, nor are Windows RSAT (Remote Server Admon Tools).
I myself couldn't run PGA Tour 23k on ARM (works fine on Parallels on an Intel Mac), so I can confirm #3 above. Granted, most apps for most people will run OK on ARM, but there are some limitations.