Back in my earlier days working on autonomous vehicles, I dreamed of something like this.

The issue with bounding boxes is missed detections, occlusions, and impoverished geometrical information. But if you have a hundred points being stably tracked on an object, it's now much easier to keep tracking it through partial occlusions, figure out its 3D geometry and kinematics, and even re-identify it coming in and out of occlusion.