In short: from my experience, people like map and filter , but not reduce . I use functions like map and filter all the time. When I put that code up for review, my peers rarely complain. I get plenty of feedback about other decisions, but not about my use of map and filter . I cannot say the same for reduce . Often, when I’ve submitted a patch with reduce inside, I get a comment like, “this part is hard to read.” And I see reduce way less than map , filter , some , and so on. Anecdotally, I have come to believe that programmers don’t like reduce as much. I don’t know why, but I have a few theories: reduce is harder to read. reduce is less familiar. reduce can have worse performance compared to other options. reduce is less elegant in languages I use, like JavaScript, Python, and Swift. In my blissful stint as a Clojure developer, I did not get this feedback. I’m wrong, and I’m seeing a trend that’s not real. I usually just change reduce to something else and move on.…