Movies and TV Shows

You're misunderstanding the argument and offering a pretty facile counter-argument.

The misunderstanding is narrative v aspiration. We are talking about movies and tv shows for children, like Star Wars, the MCU, Star Trek etc. No one is saying people don't understand or can't relate to a narrative if the characters don't resemble them. The argument is that non white kids should have large, classic, mainstream heroes who resemble them too. Rather than just the Enterprise's tactical officer or engineer but rather, the captain.

Meanwhile, the argument that content producers are trying to tailor the consumer to the product is, at best, a rather silly notion. If anything, content producers want as broad a base as possible. Unless you believe Netflix wants to be Blackflix, Prime as LatinoPrime etc it's just nonsensical on its face. And the idea that content producers want us only to care about diversity just comes right out of a silly right wing playbook where any discussion of race or gender is indoctrination being foisted on the unwitting masses. In reality, the folks who complain about the very notion of race swapping a classic character seem to be the ones obessed about race ("Oh no! An imaginary space captain is a different skin tone than the first actor who played that pretend space man!") The simple truth that most media, for pretty much its entirety, has catered to white men. Things slowly started improving so that women and minorities could participate but rarely as the lead. Now, people are rightfully looking at that as boring and as outdated as Leave it to Beaver.