The European Commission yesterday adopted new exemptions to its Batteries Regulation that free the Apple Watch and AirPods from having to offer user-removable and replaceable batteries. The EU's Batteries Regulation generally requires consumer products sold in the region to let users swap out their own batteries, a push meant to keep devices in use longer and make it easier to recover materials for recycling.
There’s no reason Airpods couldn’t have a removable/replaceable battery. It’s also questionable that the watch couldn’t either.