They quoted what matters the most as it's for a device which has single shortest runtime on a battery: the Switch console itself.

Because who cares if the controller lasts 27 or 30 days? (Or so, don't quite me on exact numbers).

The console one seems the only relevant one. I'm a casual gamer, but the joycon running out of battery doesn't feel that annoying to me. That 16% has a much smaller impact on the JoyCon than on the main device.