> But for the life of me, no forum post or FP tutorial that I could find explained monads in clear language. I've googled "what is a monad" once a year, only to get the vague idea that you need monads to handle IO.

Another phrase to search for is "railway oriented programming"[0], which technically describes a monad called a Kleisli[1]. Still, there are many introductions in a lot of languages based on the term above.

HTH

EDIT:

Something to keep in mind is that the term "monad" identifies a mathematical concept having well-defined behaviors, not a specific construct. So searching for "what is a monad" is akin to searching for "what is a happiness."

0 - https://medium.com/geekculture/better-architecture-with-rail...

1 - https://bartoszmilewski.com/2014/12/23/kleisli-categories/