Windows is just shit piled on top of shit and sold as something new. It's so bloated so they can maintain backwards compatibility. So original code is definitely in Windows 11.
Ever hear of Windows NT? Legacy DOS code was relegated to userspace long ago. And NT was designed by Dave Cutler, the guy who designed VMS and RSX-11. Most certainly not "shit piled on top of shit." Unix could have learned a thing or two from Dave but by then it was too late; the plane had very much taken off.