Like other comments, I bought a bunch when they were released and have them in all bags/suitcases, kids' school bags, and of course, keys. I've never lost a wallet or keys; heck, wake me up from a slumber, and I will tell you exactly where a particular key or an object in our home should be. But I love these things -- tiny trackers, phone calls on your Apple Watch -- growing up with Star Trek in the 80s/90s will do that.
Fun anecdote: right now, I have tagged my father-in-law with an AirTag while he is in town for his medical check-up. He is notorious for just taking off trying to find an audience to speak with, ever since the family barred him from accepting speaking invitations to conferences. Recently, we tracked him talking to a bunch of Bangladeshis at a hospital about why they should learn the basics of English.