I agree with your sentiment, but because pup knows CSS selectors and understands the page hierarchy, this will blow the doors off of any line-oriented tool. I'm also stoked about the pretty-printing, but that's just from reading the English; I haven't actually tried the tool yet.
I agree that jq is a must, along with httpie, and now pup. Thanksfully, jq is now in all distros I've tried (except Arch Linux), I think httpie is as well, so, let's hope same happens to pup.
I also agree with the author: jq is invaluable.