Many seem to like the Granny gear in the front as kind of a one trick pony. And that’s how they use them on the mega range cassettes. I don’t care for just having that one choice when on the Granny and looked at it as if you have a triple why not give yourself a good 6 granny gears to pick from and avoid making shifts up front while climbing. Rear shifts are much easier shifting off the bottom of the chain line where it isn’t under tension while climbing. Also keep in mind a 3 tooth jump on the bigger gears is about the same percentage wise as 1 tooth on the small end of the cassette.