I remember Pearl Jam challenging them in the 1990s:

* https://www.rollingstone.com/music/music-news/pearl-jam-taki...

> In May 1994, the grunge band Pearl Jam filed a complaint with the U.S. Department of Justice claiming Ticketmaster had cut the group out of venue bookings in a dispute over fees.[50] The investigation was closed without action in 1995, though the Justice Department stated it would continue to monitor the developments in the ticket industry.[51][52]

* https://en.wikipedia.org/wiki/Ticketmaster#Anti-competition_...

> By 1994, Pearl Jam was "fighting on all fronts" as its manager described the band at the time.[43] Reporter Chuck Philips broke a series of stories showing that Ticketmaster was gouging Pearl Jam's customers.[44] Pearl Jam was outraged when, after it played a pair of charity benefit shows in Chicago, it discovered that ticket vendor Ticketmaster had added a service charge to the tickets. Pearl Jam was committed to keeping their concert ticket prices down but Fred Rosen of Ticketmaster refused to waive the service charge. Because Ticketmaster controlled most major venues, the band was forced to create from scratch its own outdoor stadiums in rural areas in order to perform. […]

> The United States Department of Justice was investigating the company's practices at the time and asked the band to create a memorandum of its experiences with the company. Band members Gossard and Ament testified at a subcommittee investigation on June 30, 1994, in Washington, D.C.[52]

* https://en.wikipedia.org/wiki/Pearl_Jam#Vs.,_Vitalogy_and_de...