... for some definition of "easiest." Maybe I would agree if you don't need to support a custom look-and-feel (Win32-looking apps don't really fly anymore), responsive layout, high DPI, touch/pen input, system theme colors, accessibility, localization, and haven't learned XAML.
Win32 is the style that Windows apps are supposed to be and what people expect in a Windows app. What are you talking about? In what way does the win32 look "not fly"?
I've tried to use WPF and it was just a major pain and felt like a mess. There is no impediment to "responsiveness".
Where did you get the idea winforms apps don't follow the system colors?
> Win32 is the style that Windows apps are supposed to be and what people expect in a Windows app.
Maybe in the Windows XP era. None of the built-in apps in Windows 10 look like Win32 apps, apart from legacy stuff that hasn't been ported yet and now looks sorely out of place.
WPF and UWP apps are both far easier.