Actively supported versions of windows still supports 4 architectures for apps (x86, x86-64, ARM, and ARM64) and long term at least 3 of those (both c86 and ARM64) aren't going away (32 bit as an install target is but not as an app type which you might need depending what your app does) so everything as a fat app isn't a great choice like it is on macOS where there are 2 options and long term there will be just 1.
That said you can still achieve something similar. Windows comes with the x86 emulation layer enabled by default on all system types so if your installer is packaged as x86 you can have it contain multiple install packages and select based on the system architecture. This is known as MSIX bundling. Alternatively for online installs the installer can just be the thing that grabs the right version for the machine and launches it.
Of course it's more work to create a fat app style bundle so most don't bother. The possibility is still there though.
That said you can still achieve something similar. Windows comes with the x86 emulation layer enabled by default on all system types so if your installer is packaged as x86 you can have it contain multiple install packages and select based on the system architecture. This is known as MSIX bundling. Alternatively for online installs the installer can just be the thing that grabs the right version for the machine and launches it.
Of course it's more work to create a fat app style bundle so most don't bother. The possibility is still there though.