Don't get me wrong, I like funcional programming, but this smug „This would neeever happen with FP“ bullshit really gets on my nerve and kind of turns me off the idea of ever wanting to work with FP programmers.
It's just another paradigm, it's still possible to write unmaintainable fuckugly crapcode with functional programming.
And it is still very possible to write beautiful, clean, well maintainable code with OOP. Get over yourselves and understand that it's a tool and not a religion, and a good dev should know when to pick which tool for which job without childish notions of intellectual superiority.

Fair point made.
I mean I do employ FP where I can but my code isn't clean because of FP.
Both can produce ugly messy code depending on how well a person understands either FP or OOP or any other coding style/paradigms.

As an ex-FP programmer (2 years professional Haskell) I fully agree.

There's also a shocking amount of people who think that the power of Haskell comes from the FP paradigm, and coming from PHP, JS or Python it might seem like a miracle cure. But I'd argue that it's the incredible type system which makes Haskell great for correct programs.

JS and Python are also like three quarters FP, and while that has advantages in terms of conciseness, it doesn't magically make code correct.

What I am excited about though, is that the most useful concepts from the Academic Circlejerk that is FP are leaking into other languages such as Java, Kotlin, Rust, ES6, TS, Go, etc — both in terms of advanced type system features, and succinct higher order function notations.

Pureness and isolating side effects is more of a mindset thing, and can be applied effectively to OOP as well.

I think this sums up the usefulness of FP pretty well:
https://youtu.be/iSmkqocn0oQ

Also, by merit of how iteratively computers work (a CPU is not some magical lambda calculus machine), it's very difficult in FP to optimize for performance.

Parsing values from a json file with an array of users to xml using a lens and some maps and filters works wonders for writing logically correct and nicely composable code — but somewhere under the hood it's being translated into a whole bunch more iterative loops than you'd use manually.

Every paradigm, every language and every framework comes with a bunch of tradeoffs.

A fucking men! I see this language war bullshit so often that I'm fucking sick of it.
@bittersweet I completely agree with you