A 10-Year Battery for AirTag

Are AirTags actually useful for anti-theft purposes?

I threw one in the trunk of my car (just in case - I ordered a 4-pack and I had a spare one), and every single time I drive somewhere it chirps loudly when I'm exiting my driveway, making its presence immediately obvious without any delays, and despite my phone being with me in the car.

There is something wrong with your configuration/setup, it is not supposed to start chirping unless it is out of range of your phone for at least 8 days, and not in one of the predefined geofence regions you can setup where it won't chirp.

I have them on tons of my devices, including my kids personal items that go to school, etc. and they never chirp, and I can and have found items that were misplaced in public locations (but not actually stolen).