Customer Service desk experience two types of tickets: some are one offs, unique tickets that can be handled on a 1:1 basis. The other type are a wave of similar tickets created because something broke, changed or got disrupted.
Both scenario's can and should be handled by a good self service flow. A customer who forgot their password should easily find the article explaining the password reset procedure, and your bot should offer this article in return to any inquiry about loss passwords.
But sometimes something bigger breaks. A ship blocks a canal and all your deliveries are delayed. Your authentication platform experiences downtime and no customers can login. These kind of events often trigger a long list of tickets related to the issue, and since these issues are structural, they can't easily be solved at once.
This is where the Problem and Incident feature of Zendesk comes to the rescue. The Problem tickets option allows you to create a single parent ticket (e.g. "Authentication issues") and link all tickets from customers reporting the issue as incidents under that one main ticket.
Any update you do to the main ticket (e.g. "we expect to resolve this issue within the next hour) will get send to all customers, and you can get a clear insight in how many customers reported the issue, and more important, are still experiencing issues after the main event has been resolved.