You can write a confusing unreadable Haskell script, just like you can write a confusing unreadable Python script. There’s nothing magic about functional paradigm programming.

It does, IMO, give you less foot guns related to state though. While I still actually like other paradigms, functional programming really limits how clever you can be with state. You can only pass things around immutability via parameters (At least with Haskell specifically) instead of making a confusing taxonomy of objects with unique APIs, for example.