Besides examples like this one.
The amount of issues on Github across all WinUI related tools, keeps increasing all over the place, there is almost no visible activity, the community calls have been a disaster with Q&A being ignored, team rotation, whatever.
Native AOT still cannot do what .NET Native did (there is a CsWinRT 3.0 that supposedly is going to fix that). Additionally it requires all classes to be marked partial classes.
C++/CX was killed, replaced by C++/WinRT without any Visual Studio tooling, meaning using it is similar to using ATL during the Visual C++ 6.0 days. The experience promised at CppCon 2017 never came to be.
Additionally hidden in a comment thread on its Github repo, the original devs that are now working on windows-rs, mention that C++/WinRT is in maintenance mode, it won't be further developed.
Ah, and they are open sourcing WinUI, guess how many devs are still left to work on this.
Really, from someone that used to advocate using WinRT back in the Windows 8.x/10 days, stay away from any technology that is somehow related to WinUI.
Microsoft themselves can do whatever they feel like with WinUI, it comes with the job, the rest of us, better use Win32, Forms, WPF, Avalonia, Qt,...
EDIT: I forgot to mention in its present state, the application identity and COM reference counting required by WinUI, makes the "blazing fast C++" components actually run slower than typical .NET applications. The irony from the folks that kind of sabotaged Longhorn efforts, and went ahead redoing the ideas in COM.
This explains a lot about why the Start menu has felt sluggish compared to Windows 10.
The React → WinUI migration is the most technically interesting detail imo.
If MS really wants its users back, many of which have left for Linux and Mac, it should seriously consider going back to the Win7 era UI, or at least restore the Windows Classic theme.
Using React for it was probably done since it's just objectively easier and faster to tweak a React app than native components (see various folks complaining about WinUI).
Not only has Project Reunion been a disaster (moving UWP regular Win32), apparently Microsoft new employees lack Windows experience, being raised in Chromebooks and Macs, apparently they aren't getting the trainings they should.
You can go watch recordings of the community calls, and see puzzled faces when asked about Windows capabilities not yet supported on WinUI/WinAppSDK.
They should be given Petzold's famous book on the subject, published by Microsoft Press itself.
That leaves „web technologies“.
React Native is a way of orchestrating a UI comprised of native controls.
If you can't make it better, make it worse, it seems.