io_uring does more than IOCP. It's more like an asynchronous syscall interface that avoids the overhead of directly trapping into the kernel. This avoids some overheads IOCP cannot. I'm rusty on the details but the NT kernel has since introduced an imitation: https://learn.microsoft.com/en-us/windows/win32/api/ioringap...

IOCP is great and was ahead of Linux for decades, but io_uring is also great. It's a different model, not a poor copy.

If that were true then presumably Microsoft wouldn't have ported it to Windows:

https://learn.microsoft.com/en-us/windows/win32/api/ioringap...

Although Windows registered network I/O (RIO) came before io_uring and for all I know might have been an inspiration:

https://learn.microsoft.com/en-us/previous-versions/windows/...