That's just what commercials are like. Here's a verified real American commercial: https://www.youtube.com/watch?v=G-T3qKl6y-c

Dumb people are less sensitive to all types of sensory input - This is why they tend to be loud, sensation seeking, and seemingly unaware of how annoying they are. As the tv and ad watching population becomes dumber, through migration, aging, and self selection (there is an intelligence barrier to using adblock or alternative sources of media), then the ads need to become more stimulating to have any effect on the target's nervous system. So louder sounds, exaggerated expressions, bright colors.

Side note: this pattern is apparent in LLMs and image generation AI. Some models won't do what you want at first, but if you yell at them or threaten them, they will. Sometimes just repeating the keyword over and over works. There was a paper recently where a type of reinforcement learning still improved results even if you gave rewards randomly instead of only for correct answers. This was because the reinforcement learning wasn't actually doing anything except amplifying the existing circuits, making them more sensitive it input.

This is also apparent in the smoke detector phenomenon. A short sharp sound is not enough stimulation to activate the nervous system of a profoundly stupid person.