Out of the box 4K monitors don’t work on every Linux distribution. You need to modify them after but you can’t if you are using 4K. You need a 1920x1080 or smaller resolution first before you can use 4K. I should have said out of the box you can’t use 4K.
You don’t know what you’re talking about. Go and check every distros default DPI it’s literally higher than the allocation so it physically can’t work unless you manually change the DPI.