The issue I've encountered with memorizing openings is that it assumes both sides are playing perfect openings that complement each other. In reality, in my "lower rated" games, my opponent is likely to make suboptimal moves against the opening I memorized. There are ways to punish their moves, but I would've needed to memorized that. So, I have to come up with changes to the memorized opening on the spot.
Going through the checklist allows me to play without memorizing movesets even though the moves I make are not the "best".
