From the screenshot it looks like an UWP app. So it's not a "proper native" win32 application.
WinUI 3 can be used in a 'proper native' win32 application. https://learn.microsoft.com/en-us/windows/apps/winui/#compar...
Yes, it's all very confusing and Microsoft has done a terrible job of making this easy for anyone.
I'm having a really hard time thinking of any greenfield Win32/WinForms apps I use on a daily basis that were created post 2010 or so...