Commercials are very significant, sociologically speaking. Advertisers spend mountains of money trying to influence viewers to buy their products and services. Hence, when the demographics of commercials are distorted, one has to ask, Why?
Why do Cadillac commercials usually show a Black female driving their cars? How many Black females actually buy a Cadillac? It is a number approaching zero.
As noted above, POC's are grotesquely over-represented in television commercials. Couples with a white male and a Black female are common, even though that combination is microscopic in the general population. Sexual irregulars comprise a couple percent of the population (by actual polling), and yet they are about 20-25% of the characters in scripted television. Indeed, every program that shows a group of people incudes at least one sexual irregular. The Jerry Seinfeld show COULD NOT BE CAST today the way it was in the day it was made. Could not happen. There would have to be at least one openly gay character.
Sadly, one relatively recent innovation - the introduction of fat people into commercials - is actually more reflective of the general population, but still, is this the image those advertisers ought to be showing? A group of fat people lining up at the counter at Burger King? It's real, but is it wise to show it realistically?