Club and travel exist for the admin salaries, no other reason. Take away those salaries and see how long the organizations remain.
I think they are useful, but anyone who says club, aau, travel is superior to HS is most likely benefiting from selling parents the thousands of dollars a year dream, and almost all a parents I know who have went that route, spent more on travel than they got back in scholarship.
It's gatekeeping, and then we wonder why we aren't getting the best athletes in all sports now. Look at USA mens soccer, total gatekeeping programs, and they have the best facilities, best everything, but still can't get the best athletes because of this nonsense.