I used to use a pair of Apple’s 1st generation AirPods regularly, they fit and stay in my ears just fine, and I very much looked forward to active noise cancellation back then. But the batteries deteriorated over time, to the point where I had to keep one pod in one ear while putting the other pod back into the case to recharge, all within the same hour-long conference call; worse when I had to do back-to-back conference calls.
There is no true “battery replacement” service for AirPods. Whatever Apple calls “battery replacement” for the AirPods, they basically swap your old AirPods with new ones, and the cost was very high, close to buying new ones anyway. The olds ones just become electronic waste.
Between the short batter life, the monetary cost, and the environmental cost, I just stopped using AirPods and went back to using wired ear pods.