C# hasn't been an issue for me at all bar a few oddities. Some things not working properly in C# (think some plugins or something back a while ago). Some code not directly mapping from GDScript to C#, causing huge object count issues. For reference, I've been using it since 3.1 in a hobby context.
Really, it's not the developers you have to worry about. It's everyone else. Godot is made with developers in mind, but there's much more to do than wiring signals and writing code. If you can't map things one to one from a different program or close to that through a plugin, you're either giving yourself more work, or forcing not just developers, but artists to relearn processes too.
> If you can't map things one to one from a different program or close to that through a plugin
I've only used Godot in a hobby context, but the full on C# support compared to other engines is pretty amazing. Just as a proof of concept I imported an open source C# library I've worked on that's designed to play old DOS music formats, created a small wrapper node with control functions, and I was able to control it as expected from within GDScript nodes right out of the box. Only issue I would have seen down the road would be cross-platform compatibility since the library itself was Windows only.
Caveat: I can't say I've ever got far enough in Unity to say if the C# support is of a similar scope. Godot just "clicks" better for me, so I've gotten way farther with it than anything I've done in Unity.
Yeah, that works well. Most libraries do work depending on target platform. With C#, you can write your entire logic outside Godot and just use Godot as a graphical interface if you so desire.
But that's the point. We're discussing things from a developer point of view. This happens almost every day by now. That's not the issue. The issue is how everyone else struggles with Godot compared to Unity, if at all. When even basic particle patterns require diving into shader logic in 3.4 or loads of trial and error, that's a pretty hard sell for non-technical people.
Really, it's not the developers you have to worry about. It's everyone else. Godot is made with developers in mind, but there's much more to do than wiring signals and writing code. If you can't map things one to one from a different program or close to that through a plugin, you're either giving yourself more work, or forcing not just developers, but artists to relearn processes too.
The small stuff will get fixed over time.