[BlargMcLarg]

Take about anything you like of minimum level C# 6. My personal gripe being poor adoption of tuples/anonymous types and records.

C# has been trending towards introducing more things from the functional paradigm in particular, but just getting away from typical OOP patterns and replacing them with something more on the spot or functional isn't amazingly well received. The main thing which seems very well adopted is LINQ, and that's primarily due to Entity Framework and Microsoft pushing LINQ-adoption hard. Most places still program in C# as if it were Java with Lombok built-in.

And that's where I'm getting at mostly. New paradigms and languages are cool, but historically it's been difficult for them to get mass adoption unless a big name is pushing for it hard. Convergence has been the name of the game for a while now, rather than divergence.