I Don't Need Functional Programming

I think when people say, you know, I don't need functional programming because if I arrange things, I've stripped out all the OO and we're just down to like immutable values and return types. There's no downside to having everything be a pure function. 99% business applications are basically that. And so you really don't need much more than that. The mental overhead of having to train somebody on all the complicated stuff is pretty straightforward for people to understand.