Ask HN: Why hasn't there been a real competitor to Ticketmaster yet?

It feels like every event/venue is selling tickets exclusively through Ticketmaster. Every other ticketing platform seems to only hold resale tickets in their inventory which just transfers the tickets to your Ticketmaster account when bought. With all the hate Ticketmaster has gotten and all the other ticketing platforms out there, I'm surprised Ticketmaster still has a hold of pretty much the entire market. How are they doing this? Why haven't the other platforms been able to compete?