This dictionary stuff is truly bizarre. I have been playing around with GDExtension and Rust - specifically the meshing interface. This dictionary stuff shows up there. Not only couldn't I figure out why (the GDScript angle makes sense in hindsight), but it also makes the API virtually impossible to discover: you have to resort to reading things up in the documentation.
As much as I love Godot, the GDExtension interface really has no redeeming qualities and needs to go back to the drawing board.
As much as I love Godot, the GDExtension interface really has no redeeming qualities and needs to go back to the drawing board.