It’s unaffordable because many people are inherently selfish and want to live in desirable locations as opposed to the already afforable areas that the majority land-mass of the USA consititutes.
I dont think that's it at all. Even in "undesireable" places the rents approach what a median income earner can afford anywhere. It's akin to why we have minimum wages. Without them people will work (out of desperation) for pennies because they have to.