There are plenty of both really, too many perhaps

Hey! We have buff, and plenty of local pubs! The other things are true though, can’t help you with those

Yes, my thoughts exactly.

This problem is not solved by monads, but by higher kinded types in general in languages like Haskell. They give you a uniform way to be generic over effects like async (Async) vs sync (Identity). Both of these can be treated as (F) for all A. So a generic Into would look like the following, and no special syntax or semantics would be needed. The type system (if sound) would prevent you from misusing a trait like this.

trait Into {
   def into(self): F;
}

This seems to have many similar ideas as Dhall Lang - https://dhall-lang.org/