Answer: Magic just looks more... magical?
A broomstick zooming through the grounds of Hogwarts of its own accord as Harry shouts “accio broom!” is just way more impressive if the screen you’re watching it on has ample real estate; likewise the effects of Polyjuice Potion (particularly when they go wrong), slipping into the Pensieve, flying cars and every single magical duel. Unfortunately, the giant spiders also get bigger.
Explanation:
