In my experience (OP's post resonates highly with me, I've also been dabbling in Haskell for a while and consider myself somewhat competent), it's a long term i

In my experience (OP's post resonates highly with me, I've also been dabbling in Haskell for a while and consider myself somewhat competent), it's a long term investment. I've been at it on and off for a while and even though I haven't done anything "useful" with it (except Uni coursework, which I convinced my teachers to mark in Haskell), I feel like I've grown a lot as a programmer thanks to it. Understanding concepts functors, applicatives, monads, lenses etc is a reward in itself, at least to me. Sometimes I write small toy programs, like a sudoku solver, which lets me get a glimpse of the true power of languages like Haskell. But at the end of the day, I agree with the general intent of your message (and OP's post) - different programming paradigms change the way you think about programming, and generally makes you a better programmer.