You can't run Windows 3 software on Windows 11. You could on 32-bit versions of Windows 10 (after adding some optional Windows components), but Windows 11 is 6

You can't run Windows 3 software on Windows 11. You could on 32-bit versions of Windows 10 (after adding some optional Windows components), but Windows 11 is 64-bit only and 64-bit Windows can't run 16-bit (or DOS) code at all. So, hypothetically, at least in the Windows world, we're approaching a point where some of the legacy cruft could go. Not quite all of it yet (still need 32-bit application support), but a lot of the 8086-era real-mode stuff will never be used on modern hardware running modern software (except perhaps for the first few instructions after boot, until UEFI pushes the system into 32- or 64-bit protected mode).