[pjmlp]

Kind of, Windows 11 WinRT components are still based on UWP, as WinUI 3.0 and WinAppSDK aren't yet up to the job of replacing it.

WinRT hasn't died, that is what WinUI 3.0/WinAppSDK is all about, making that COM infrastructure available on the Win32 side, even though their progress is quite slow.

I think it will take them 2 years still to reach feature parity with UWP features.

[ComputerGuru]

You have it backwards, UWP is based on WinRT (which is built on top of the COM underpinnnings) and not the other way around.

[pjmlp]

Having used it since Windows 8 days, I know pretty much how it all goes.

Nowadays there are two WinRT models, the original underlying UWP that grew out of the UAP / WinRT evolution introduced in Windows 8.1, to simplify what was originally split across phones, tablets and desktop.

And now the WinRT implementation on top of Win32, started as Project Reunion, rebranded as WinAppSDK alongside WinUI 3.0.

[ComputerGuru]

I’m not trying to be particularly pedantic but that still doesn’t make WinAppSdk built on UWP; it’s mainly an expanded and cleaned-up collection of first-party cross-language wrappers/bridges/ffi to WinRT to hide the COM underpinnings plus unify some of the disparate Win32 vs WinRT APIs.

As you know, WinRT predates UWP. UWP as tech isn’t strictly defined but it includes things that are out of the scope of WinRT itself and aren’t available via WinAppSDK even now that UWP is finally, officially dead.