Only kids from wealthy families can afford to move to say DC or NY and spend a year there on an unpaid internship. So that becomes a selection criteria to exclude those from poor and middle classes from advancing in those domains.
The same is true for entry-level media jobs. Paying $40-$50k in NYC... you can be sure kids without generational wealth & parents financial assistance choose other paths.
This is definitely untrue. There are plenty of young people willing to save roughly no money for the early years of their 20s by trying to make it in the big city in a flashy career. I know several who don't get any financial support from their parents (and certainly don't have generational wealth). The most you can say is that people who have parents that _require_ financial support aren't able to take this path, but that's a significantly smaller group.