Earlier quoted context omitted.
This indeed. Custom UI widgets for Windows apps are really not necessary most of the time, and fitting in with the system theme is all you ought to aim for, most of the time. There are exceptions, for very rich dense UI, for UIs that need to be cross-platform, but if you're writing a Windows app, it should look and feel like a Windows app.
> There are exceptions, for very rich dense UI, for UIs that need to be cross-platform That’s not exceptional at all. That’s completely normal requirements that are probably in the majority. Does Microsoft themselves build their apps this way?
You need consistency in the icons, layouts and concepts, but you don't need every widget to look exactly the same on every platform.