The problem with this is nobody is performance managed on PR reviews. Features are often what get put on performance reviews, so it becomes beneficial to the PR author to go work on another feature than review someone else’s PR. Reviewing a PR for a feature doesn’t get your name attached to it. More often than not, your review is considered a formality imposed by upper management and impediment to the feature in the eyes of line managers. Those headwinds turn PRs into a classic Volunteer’s Dilemma [0].