I recall a time when product sponsors like Rockstar Energy Drink were unseen, yet metal bands would pack a stadium concert for one long night without the sponsorship crutch. You would find 2 or 3 major bands that everyone listened to like perhaps Accept, followed by Judas Priest, then Dio as final act for example. Now it is typical to have what is called a metal festival with 28 in the lineup, 6 of whom everyone has heard before and 2 that worth seeing.
The corporate sponsorship pretty much just functions as welfare for the two dozen useless performances in the lineup. So you have to put up with the vast host of dullards in addition to the advertising pollution to even have a shot at something good. This is all like a reflection of the larger surrounding society.