A pair of AirPods weighs the same as two ordinary plastic bags, the grocery store kind.
Lithium? About a gram of lithium in a disposable AA lithium battery. About 0.015 grams per AirPod proper, and another 0.16 grams in the case. So call it 0.2 grams, or when you toss five (5) AirPods with their cases, that's as much lithium as one (1) disposable AA battery.
AirPods weigh 10.4 grams for the pair. Let's say two hours per charge, and 400 charges, before they're no good.
That's 1.3 milligrams of e-waste per hour. After 77 hours you have one aspirin pill's worth of e-waste on your conscience.
Filling a landfill? With the case, I get about 1.5 million per shipping container. How big are landfills where you live?