Marcel Hirscher uses all the Essentials of skiing, and he does them better than everyone else on the World Cup. The Essentials are, Tipping the boots, feet and legs, (especially the inside boot) Counter balancing the upper body, Counter-acting the torso and hips, Flexing one leg while lengthening the other, and using Fore/aft balance.
Marcel uses all the Essentials and he creates them more cleanly while holding them and using them with perfect timing. No other skier, tips the inside ski as far and keeps it as close to the outside ski as Hirscher. This is only one of his huge advantages he uses over the competition.
Here is an example of his inside ski tipped to a high degree, his inside leg flexed and the long outside leg. Again here you see his strong counter balance of the torso. His torso is vertical, legs and skis are at high angles. Many coaches think this is old school, I think it's an Essential every skier must have. He rarely rotates his body when blocking, or steps his inside ski out of the turn. He keeps both skis and feet close and finishes by transferring to the little toe edge.
If you spread or step your inside ski, it takes much long to transition and you lose speed and pressure.