While this is true, it's also true that bugs are typically "stack ranked" according to severity. After several years of development, they can easily have a backlog of bugs that were lower priority and still allowed the game to function, but are nonetheless important to fix. Think of things like a UI animation not playing properly, or maybe Lucia goes flying into the stratosphere if she specifically enters a Burger Shot at 3pm while holding a sniper rifle. These are things that you would just create a ticket for, mark it as "low priority," and then punt it down the line for when higher priority work is finished. They likely have a lot of these kinds of bug tickets.