They don't leak would be why I would choose these over an alkaline battery. The draw of an airtag is so low that the shelf life becomes very material.
I also put lithium AA/AAA batteries in remotes these days - anything that might get stuck in a drawer for years at a time and needed again for a random task. My A/V receiver remote is rarely touched, but when I need it I really need it. Too many times have I went to grab some device like that only to find the batteries have leaked and corroded a critical component on the PCB.
Doing some math, looks like a CR2032 is roughly 200mah while AA is 2000mah. So if CR2032 lasts one year, then the AA will be 10 years, two AA would be 20 years. I guess in that case lithium would be the way to go.
I just know for your typical wall clock that takes a single AA, whether it is lithium or alkaline, both won't make it much further than a year.
The advantage of "lithium" is high rate discharge, not longevity right?