You should realize that venues and artists are equally beneficiaries of what Ticketmaster enables. In a sense they enjoy having Ticketmaster be the hated scapegoat for high prices that they then also enjoy the benefits of.
Without Ticketmaster who knows how much less tickets would sell for. And venues get paid a cut by Ticketmaster. Artists get paid a cut by Ticketmaster. Sometimes those parties are glad for that value extraction from the concertgoer to be done on their behalf, and to be blamed on an entity that diverts attention from the fact that they want more $ too.
Ticketmaster did not just emerge to prey on an unwilling helpless industry. They occupy a niche that is part of a semi willing ecosystem.