The big reason that there is a difference is because of improper shielding.
It's nothing to do with shielding (both cables have the same composition), the component cable eliminates cross-talk between Y/Cb+Cr signals by sending them on separate wires. Rather than showing the difference in cables, that comparison shows the difference between 480i and 480p which can vary greatly between different TVs - a 480p signal effectively sends each line at double regular speed, some TVs only process the signal at regular speed (discarding half the information) and scale horizontally causing blur.