The whole .COM/.EXE thing is not limited to 16-bit DOS and Windows. For a very long time now, Windows simply treats both extensions as the equivalent of chmod +x, but the way the binary is loaded does not depend on the specific extension. That is, if a .COM file has a 64-bit PE header, it will happily execute on Win11.

Indeed, a bunch of system binaries are themselves like that for historical reasons - CHCP.COM, FORMAT.COM, MORE.COM etc - because they originally had such names long ago in DOS, and someone somewhere might have a batch file that includes the extension.