Just as Uber doesn't provide transport, Ticketmaster doesn't sell tickets. They characterize themselves a broker, someone facilitating sales between "Event Providers" and customers. They will pass the responsibility to concert organizers.

A lawyer would describe most "Event Providers" as judgment proof, ie too poor to be worth a lawsuit. These aren't the rockstars nor their touring companies. The event provider is the local organization who rents the venue and manages the individual concert. They are all currently shut down, employees laid off, and are likely talking to bankruptcy experts.

For example: Vancouver just cancelled its jazz festival. That festival's "event organizer" is the "Coastal Jazz & Blues Society" ... a listed non-profit. There is no blood in that stone.