I bounce back and forth between javascript and C# depending on the nature of the job at hand. I'm curious what things you'd like to do with C# that you can't?
I find that with some handwringing, C# can be forced to do almost anything. between extension methods, dispatch proxies and reflection you can pummel it into basically any shape.
Having to write a little boilerplate to make it happen can be a drag though. I do sometimes wish C# had something from a blank project that let me operate with as much reckless abandon as Object.assign does in js land.