It's not something that Apple openly markets as being a reason why you should buy them so my guess would be a lot less than you think, because of cost to do so.
No it doesn’t, agreed. But I imagine the design constraints for a notebook vs. wireless headphones are pretty different. I am amazed that the thing can be built at all.
Whereas with Macbooks they openly tout that https://www.apple.com/environment/
"Built to last as long as humanly possible." -- Apple
That doesn't sound like an Airpod to me.