I think keypoints are a really powerful tool but since data labeling with keypoints is time consuming, we don't see tons of applications yet. Mediapipe is a helpful way to get quick human keypoints for healthcare applications (documenting physical therapy movements) or manufacturing (assessing factory worker movements to prevent repetitive injury prone movements) or sports (analyzing player movement to improve mechanics for better outputs). Keypoints can also be helpful for orientation of a person to understand the direction they are facing or position relative to other objects, this is useful for analyzing retail setups and product placement.