Event Is always one, but the ticket type is multiple. One event could have various ticket types. Users select multiple ticket types, not multiple events. So, the Quantity column on the Cart page shows 1 for the event. But in the Event name below, you can see the ticket type, quantity, price, and event date details.
It’s not possible to change the quantity on the Cart page. It will create an attendee duplication issue in the event booking.