Monads let you redefine what a statement is. This is very powerful and makes Haskell my favourite language for imperative programming. There's no need to modify

Monads let you redefine what a statement is. This is very powerful and makes Haskell my favourite language for imperative programming. There's no need to modify the compiler for e.g. Async/Await, it can be a library. A Monad instance has a set of properties or laws that it obeys. This gives you a general understanding of what e.g. filterM will do, i.e apply an effectful filter function such that the effects are sequenced in the order of the input list.