The HTML based UI ecosystem is just so much richer and better supported than WPF that any theoretical advantages WPF might have are dwarfed by the practical considerations of just build it in Electron and be done with it.
You may be right :-)
OT: At one of my former employers we were building a PLC. The sister team was building the IDE to program the PLC, and the compiler.
All of us were behind schedule. But our colleagues from IDE world staged a presentation for the whole project including top management (owner, CEO etc.) where they showed how far they were.
They showed how they have multiple windows inside the main application window, minimizing and maximizing those. Syntax highlighting. Basically everything Eclipse is giving you for free. Actual business logic: none to be seen.
Now they are working on cross-platform and that's why it had a feature freeze ( + because of graphics). It's now being added in .net core though.
So it's not dead at all