Well I remember some screen shots of people getting their AirTags and showing 2019 and 2020 on the box so if they were in the box that long, and I have no way of knowing of course, but I could see the battery being close to dead because I think the are to last a year under normal use so sitting around for a year or two could weaken the battery.
That makes 0 sense,..there were plastic tags between the battery and connector. They weren't active since 2019/20. You can leave watch batteries out for years without using them.