yea its tough, when it comes to frontend you can go really fast because reviewing is easy since its something you can visually pick. for backend its exactly as you described, perhaps the ideal thing you could do is speed up your review by using ai rather than going over every line or spend more time planning and writing the spec.

I was the same when i just started using codex, i dont know the exact time but at some point i just stopped reviewing, dumb but the more i used it the more lazy i became.