Yeah. It's kinda funny. Due to extensive F# -> C# -> Java feature bleed you can consider them beta channels of the same language. Java being LTS, C# - main, and F# - Dev Builds.
And you are forgetting the ML -> F# / Scala part.
Also despite all its high and lows, the .NET story regarding desktop frameworks is much better than Swing/JavaFX, and whatever Google has butchered Java with.
However I have never been a X Developer, I always have used both at my employers since they exist, alongside C++, depending on the project and customer requirements.