WPF and Windows Forms are starting to lose relevance in a lot of use cases. The only places where they still are a compelling presence, would be deep within the Windows/Windows Server ecosystem. For instance, you still can't write professional-grade Office plug-ins, without using WPF or WinForms.
In a more general use case, such as a classic CRUD application, for instance, you could get away with an app written in Angular or React. If you require OS-level privileges, it's easy enough to convert over to Ionic, React Native, or Electron, and get that deep functionality. Sometimes the functionality truly exceeds what you get "out-of-the-box" from WPF or WinForms (toasters, for instance are way more functional with Electron, since it leverages the next-gen HTML5 notifications). The coding experience is more REPL, and the actual code that you have to write is a lot less ceremonial (IMHO) than WPF or WinForms, so that's a big draw.
It's interesting to note, that VS Code is written in Electron. In fact, there is a significant, growing number of mainstream Electron apps.