In my past experience in IT, the ticketing system basically doubled as an aggregated event log, and it was a legitimately good use case. The monitoring software we ran on our thousands of client workstations and servers was extremely powerful and could capture any conceivable metric to use as a trigger for auto-generating a ticket.
So, a lot of tickets generated would simply just be data reports with some info dumped in the ticket description, designed to be auto-closed but possibly useful later as an easily-accessible timestamped reference to some data.
Lots of other auto-generated tickets were "probably not an issue but it should pass over the eyes of someone knowledgable about this server/network" tickets. Like Windows Event Log error roundups, CPU usage spikes, or specific triggers that were set up in the aftermath of some catastrophe to help preemptively avoid a repeat incident.
Anyway, tickets are a great "first line of filtration" where you can take a massive ingest of all different kinds of data (hardware metrics, system logs, network activity), apply meaningful human context ("This pattern could be a sign of xyz"), and store it in a unified database. With that use case, it's easy to imagine a company with millions of customers and millions of servers producing millions of tickets.