I only dabble in C# these days, mostly because Microsoft doesn’t bother porting .NET Forms to Linux, but my most recent GUI framework experiments were with Avalonia and that felt quite good. Not everything works as well on Linux (no Fluent design background blur, though I believe it does work on Windows and macOS) but functionality-wise, it’s pretty complete.
My IDE of choice is Rider, and the Avalonia plugin has some nice previewing features and a good chunk of XML/C# binding autocomplete.
There’s a paid option for Avalonia that will take your WPF application and instantly turn it into a cross-platform app, but that’s clearly focused on enterprise users (starting cost: $5k per app per platform for startups, four times that for “enterprises”, lol). I can’t blame them, though, because porting WPF to macOS + Linux + iOS + Android + web browsers + Tizen + (eventually) VisionOS by simply swapping out the SDK is pretty amazing tech.