Then you're lucky. I had iPad 2 and Air 1. Older one is completely dead for 5 years now and doesn't react to plugged cable at all, while newer charges whole day and keeps battery for 4-5 hours.
Air 3 I've got on ebay-like site holds pretty well but the same model that my partner got from official dealer had always issues with touch recognition.
The battery might have been changed once, not sure about this.