> All Windows APIs since Vista are delivered via COM.

Nope, This right here tells me you do not have much actual programming experience in Win32/Win64 apis nor of Windows Internals. The C-style windows apis are from kernel32/gdi32/user32/etc. user-mode dlls which call into intermediate ntdll/win32u dlls which then calls into kernel mode ntoskernel.exe/win32k.sys. With modern Windows there are another layer of abstractions with "Windows API Sets" (https://learn.microsoft.com/en-us/windows/win32/apiindex/win...) which decouple those user api from their actual implementation dlls.

COM is at user-mode and so interfaces to the first set of dlls only. Since the windows api breadth is vast not all of them are exposed via COM. WinRT uses/enhances classic COM but also calls Win32 api as needed. So Win32 api and WinRT api coexist with the latter providing the "modern" way to api access - https://en.wikipedia.org/wiki/Windows_Runtime But because WinRT is oriented towards secure sandboxed apps many low-level Win32 apis dealing with memory management, thread/process manipulations, system hooking etc. are limited/removed entirely from WinRT api.

For your edification see this detailed older article; Turning to the past to power Windows’ future: An in-depth look at WinRT - https://arstechnica.com/features/2012/10/windows-8-and-winrt...

Your claims must be backed up with references before asking others about their experience. I only see you name dropping and quoting historical data in all your comments which is not relevant to discussing/understanding anything.