Using something like Photino (https://www.tryphotino.io) with Blazor can start to feel like an actual good C# cross plat GUI solution but even as a C# truther I agree with you.

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.