Take callback hell. Opaque callbacks are the functional equivalent of goto statements.
Also, many functional programmers, particularly Haskell programmers, seem not to care about readability and maintainability. They're focused on maximizing their own productivity as an individual coder, and writing cool concise and abstracted code that might not actually be easy for another engineer to understand and modify.
The difference though is that good functional programming is still quite common whereas good object oriented programming seems to be rare (the one exception being microservices).