I thought the same and did just that to see if it holds true: https://github.com/sjmulder/netwake
By default you get Windows 95 styling and Windows 3 fonts. You have to opt into 'visual styles' (introduced in XP) with a declaration in the app manifest and have to manually query and use the system font. DPI awareness is also opt in and puts all the work (sizing/positioning, scaling/reloading fonts) on you. But when you do that, it does look fine on Windows 10.
Not so much on Windows 11. Some of the widgets have been updated to mimic the new style but when you put it together it looks messy and old fashioned (e.g. fonts + you don't get the new context menus).
I'm curious to learn how one would create a 'proper' Windows app without having to reimplement the system's widget styling.
(WinForms also saw a bunch of reinvestment in .NET 5 and also has a road to migrate to WinUI 3.0 controls if you really want, but I would argue that WinForms was never a "good desktop UI framework".)
Basically Microsoft had to rampup Windows Forms and WPF teams (most likely ramped down to maintenance modus), as otherwise many companies would just ignore .NET Core.
The designers, which were redone to be out of process in .NET 5, still have lots of issues.
Basically, the future is UWP/WinUI, but just like with VB 6, there are plenty of big shot customers that want their apps to keep running and aren't open to rewrites.
And in what concerns WinUI, MAUI is being built on top of WinUI (with incompatible XAML) and then there is Blazor.
Plenty of political wars going on currently in Redmond UI teams.