That’s shooting in burst mode, it shoots separate photos rather than short videos. In sports you typically use short shutter speeds to freeze the action. If you would stitch these photos together into a video, the results would look jittery because there’s no motion blur.
Video mode also doesn't use the whole sensor on most cameras because of the differing aspect ratio of film and photography and also rarely stores the raw for each frame, you'd have like 150MB-250MB per frame for that. Burst stores each individual image at full quality.
