That soon is like a decade in the making.

And with many folks going into alternatives like Godot, it means C# ends up losing the mindshare it got.

Yes, you can use C# with Godot, but most folks end up with GDScript, or GDextension.

Iirc Godot is taking the approach from both sides however and also working on a libgodot which will allow a "bring your own runtime" which I'm much more interested in than the integrated "environments" that are Unity and Godot today. I'm likely in the minority though as they only started making a library export after the all in one environment was stable enough...