What happens if my AirPods batteries die?

When Apple designed AirPods, it wasn’t with repairability in mind. In fact, the batteries of AirPods cannot be replaced.So what happens if my AirPods batteries die? Actually,even if it was charged, it could only be used for about 2hours.That means I have to buy brand new AirPods, right?
The other day, I went to the Shinsaibashi Apple Store. If I take my dead AirPods to an Apple Store and mention a specific word phrase, Apple will replace them at significant reduced price than buying new ones. If you take them to an Apple Store and mention the words “Battery Service,” Apple will replace each AirPod for 5400(JPY) and that comes out to getting new AirPods for less than buying brand new ones. The cost of battery fix is still mighty expensive. Apple will replace the battery on an iPhone11 for as little as 7400(JPY).
What makes AirPods so different?
Of course, there’s no doubt that I’ve signed Apple Care for the New Airpods Pro!