> I mean, at the end of the day, it's learning the functional programming concepts that is supposedly going to make you a better programmer. Why not just start learning those in Java, Python, JS, etc.?

That could totally be possible for many, but for me, I need something more concrete. I had read about Haskell and the benefits of immutability and agreed from a high level, but until I actually used it, I didn't feel like I understood it.