I think that's because you chose "packaged" application, these apps need to be installed so that capabilities are handled correctly.
To be fair, macOS has the same issue, although they won't show in Launchpad, they still can be indexed by Spotlight.
What you are looking for is "unpackaged, framework-dependent". This will build an application like an old-school WinAPI executable, one which expects the relevant DLLs to be installed on the host system (or distributed in the same directory).
What I'm looking for is old-school AOT compiled executable where UI framework dependency is statically compiled and trimmed.
I haven't tried it, but there's ImGui.NET (or a bit easier ImGui.Forms) immediate mode GUI. Downside is no accessibility.
Avalonia uses Skia to draw controls, although it primarily uses XAML to define UI.
The issue with self-drawn controls is that creating such framework is a lot of work, so smaller projects often have issues with things like accessibility.
EDIT: Just did hello world test with ImGui.Forms. Self-contained AOT compiled result was 7 MB.
In my case I'm looking for a C++ UI library, not .Net. Also not a fan of immediate mode GUIs either, so would want something more traditional.
I don't want to write my own, so will probably try Qt again, but might switch to a custom library in time.
These days if I were to switch from Win32 I might try some custom rendered framework which a lot of apps seem to use, or Qt.