I agree, but Monads also simplify non-blocking concurrent programming, allowing users to think sequentially, see F# Async and Haskell IO. C# had to add Async/A

I agree, but Monads also simplify non-blocking concurrent programming, allowing users to think sequentially, see F# Async and Haskell IO. C# had to add Async/Await support in the compiler and I would argue it is not as pleasant as the F# version using Monads.