So, I may be a bit unique, I have 3 of them. 2 AirPods 3, and 1 AirPods Pro 2. I usually use the APP2 for personal music listening and the 2 AP3 for (one for work and one for exercise).
I had to turn off Find My on all of them for the cases to last super long. I also turn off automatic switching of devices because I don't want my AirPods switching to my phone if I'm in a meeting on my MBP.
Doing this, I can charge my exercise AP3 case once a week easily. My work AP3 - usually have to charge it every 2 days depending on how many calls I do. But say on a vacation week? Both held their charge for the week+.
My APP2 - same thing - turned off automatic switching, turned off Find My - and these I charge the least, like once every 2-3 weeks.
I just checked my APP2, which I haven't used since mid?early? last week, the case is at 85%, and the buds are at 100%.
<shrug>. Maybe I lucked out? Also to note, these cases spend almost 100% of their time on my desk not moving.