Winforms especially is going on 20ish years?
How do you feel burned by them.
The Windows GUI tools definitely seem to be struggling. Developing native desktop apps is much rarer these days, so all the attempts to create a single toolkit for multiple form factors makes some sense. But that is actually really hard to do, and Microsoft is starting from behind when it comes to mobile frameworks.
FWIW, the last time I developed a native desktop app was WPF. I tried again recently, but my general takeaway was that you need full Visual Studio still to make it work.
To the point that many might still use Windows, but not necessarly Microsoft frameworks.
(1) Try how a default OK/Cancel WITH LAYOUT can be expressed in your idiom. If it looks ugly and convoluted, fix your design until you don't have that problem. (2) Try how a 'tools on the sides, resizable work area in the middle' works in your idiom. If it sucks, see (1). (3) Check how margins and borders are controlled and defined in your idiom. If it requires repeating '10px' 480 places all over your source, see (1). (4) Check if evenly spacing/sizing a bunch of similar components requires special handling for first or last element, again, see(1). WPF fails all of these, and several more.
Those of us that had a go at ASP, ASP.NET, ATLServer, ActiveX, Silverlight, WebForms, AJAX Control Toolkit, WebAPI, WebAPI 2, MVC, Core MVC, Razor Pages.
I'm not even sure why you're counting WebAPI in there since it's for writing REST APIs.
The graveyard of Node and JS technologies is orthogonal to the current burnout feeling in many Windows circles regarding Microsoft technologies.
To the point that, as I already mentioned a few times, I happened to do .NET Framework to something else ports, instead of the more rational migration to modern .NET.
You see the same in long time well known Microsoft partners like Sitecore, moving away from .NET.
Technologies change all the time in every stack; flavors come and go.
By the standard of the web JS ecosystem, .NET has been relatively stable.
I don't care what others do.
It is like kids on the kindergarten playground, arguing for who behaves better.
Same thing with most of Windows GUI frameworks MS built. They all use same rendering language/interface (xaml).
Doesn't matter how long they have been supported.
If by "They all use same rendering language/interface (xaml)." you mean a XML based file format to describe the GUI layout, you are right.
If on the other hand you mean a GUI description language that is compatible with zero code changes, then not really.