Again, unless you have existing Windows 8/10 applications that were written against WinRT, UAP or UWP[0], that make use of WinUI 2.0, forget about touching anything related to WinUI 3.0 or WinAppSDK, stay away from the marketing.
Exception being the few APIs that have been introduced in Win32 that instead of COM, actually depend on WinRT like the new MIDI 2.0 or Windows ML.
Keep using Win32, MFC (yes it is in a better state than WinUI 3.0 with C++), WinForms, WPF, if using Microsoft only tooling.
Otherwise, Qt, VCL, Firemonkey, Avalonia, Uno, ImGUI,....
They were even forced to revamp WPF status at BUILD 2024, given how bad WinUI 3.0 was back then, and it isn't if it got any better, apparently it is in the process of being open sourced, to see if the community can take over the mess a $4 trillion valued company cannot fix.
Really, stay away from WinUI, unless you're a Microsoft employee on the Windows team without any other option.
[0] - Can explain by the nth time the differences, if one feels like it.
Exception being the few APIs that have been introduced in Win32 that instead of COM, actually depend on WinRT like the new MIDI 2.0 or Windows ML.
Keep using Win32, MFC (yes it is in a better state than WinUI 3.0 with C++), WinForms, WPF, if using Microsoft only tooling.
Otherwise, Qt, VCL, Firemonkey, Avalonia, Uno, ImGUI,....
They were even forced to revamp WPF status at BUILD 2024, given how bad WinUI 3.0 was back then, and it isn't if it got any better, apparently it is in the process of being open sourced, to see if the community can take over the mess a $4 trillion valued company cannot fix.
Really, stay away from WinUI, unless you're a Microsoft employee on the Windows team without any other option.
[0] - Can explain by the nth time the differences, if one feels like it.