This reminds me of the story in Freakanomics about the street level drug dealers making basically minimum wage, with the majority of the money going to high level traffickers who are typically firewalled through layers of middlemen.
It's common in a fair number of places: professional sports, music, book writing (among those doing it for money), acting, law (to a lesser degree). The very top does well, even very very well. Most everyone else scrapes by--if that. Most professional jobs aren't like that. Sure senior execs can make an outsized amount of money but most of the rank and file are still doing OK.
All those other ones you mentioned rely on popularity to determine one's paycheck, which is why they are all pyramids.