Win32 provides its own components which are basically Win95 style apps, and you can draw the components using some graphics APIs by yourself.
The whole native development area is a mess exactly because making your own (decent) renderer is a huge undertaking.
I came from the WinForms world so don't pretend I don't understand Win32 programming. The fault lies with Microsoft for not investing in it more.
Flutter is nicer to scale and maybe design but it is a massive overhead. Skia still has trouble with some drivers and causes lag or falls back to software rasterization. Hot replacement while coding is pretty neat though. It runs much better on mobile devices imho.
But that "modern" style is... disgusting and repulsive. That whole dialog is bigger than one of my monitors due to how much wasted space it has.