Mainline OS's have been 64bit for about 15-20 years by this point, the point is to trim parts of X86 that isn't used when running a 64bit OS.
Notice that only 32bit kernel/R-0 is removed, but not usermode/R-3 so even when reducing this your 64bit Windows will still run clean 32bit software built for Win95 from the 90s.
Even today you need to run a virtualized 32bit OS to run old 16bit software (the negative part is if you still run a virtualized 32bit OS then it'll need to be emulated instead of HW virtualized if the virtualization solutions allowed that).
Notice that only 32bit kernel/R-0 is removed, but not usermode/R-3 so even when reducing this your 64bit Windows will still run clean 32bit software built for Win95 from the 90s.
Even today you need to run a virtualized 32bit OS to run old 16bit software (the negative part is if you still run a virtualized 32bit OS then it'll need to be emulated instead of HW virtualized if the virtualization solutions allowed that).