I wish the comments focused more on the subject of the article which is interesting and under-discussed.
I think you'll start seeing a lot more "cross platform C# frameworks" when PanGUI drops: https://pangui.io
It's a native layout/gui util by the devs of the mega-popular Odin extension in Unity, and the idea is to directly solve "good native c# gui lib" with the implementation just being a single shader and an API that is more like DearIMGUI.
I'm also planning on using it my own small 2D C# engine when it's available: https://github.com/zinc-framework
I already do iterative hot reload GUI with DearImGUI in that engine so PanGUI will work in the same way.
Unfortunately, the way they've designed it without accessibility in mind from the start means it's unlikely ever to be anything other than an after thought.
From there, you can do your front end in absolutely whatever (Svelte, Next, etc.) and your back end is the .NET host doing whatever. So it's basically making a "native webapp", not actually doing what Maui Blazor Hybrid does where it's opening a native context and injecting a webview (if I understand it correctly)