I think when they came out, not too many had the charging case. The charging case is kind of genius because when you store them, they charge with little effort (having to be plugged in) and by just taking them off for normal day stuff (bathroom breaks, lunch), you could generally get a full days usage without a problem.

Other Bluetooth headphones of the time often needed to be plugged in and had similar battery life so if you weren’t militant about plugging them in, they’d die by the end of the day or when you were in the go away from a plug.