AirPod lost warranty
why replace AirPod lost warranty
why replace AirPod lost warranty
See if this support article can provide you with the details on why you would want an AppleCare+ plan for your AirPods should you lose them. The basic limited hardware warranty only covers for manufacturing defects. It doesn't cover the theft or loss as MrHoffman has already mentioned.
The standard Apple warranty does not cover theft or loss.
AirPod lost warranty