That's a perfect example of making it overcomplicated, just in the FP direction.
C# uses exceptions for error handling. It has it's own control flow primitives. C# developers know how to work with it, everything else uses it. Why would I want to pull in a randos GH DSL and types to pretend I'm writing F# when I can just use F# that has first class support for this ?
C# is already very functional when it comes to Linq. In real world use, this just feels like extending in the same directionality while still preserving familiarity. Whereas F# does feel like an entirely different language.
Learning C# when you know TS is like learning Portuguese when you know Spanish.