And AirTags even alert those (iPhone users) being tracked so they are even less practical
It won't warn you of an AirTag someone attached to your car, unless you make it a habit to constantly press "scan" all day.
AirGuard (https://github.com/seemoo-lab/AirGuard) can do this for you, at the cost of battery life for having something scan for Bluetooth signals in the background all day. It's silly and honestly kind of sad that Apple's app doesn't provide this functionality.
Perhaps Google should add this functionality to Play Services. They already have an API capable of running Bluetooth background scans constantly in the form of the COVID contact tracing API, so the technology is nearly there already.
Wouldn't you only need to scan whenever you return to your car?
If you start scanning then and find that there are no tags, you only need to keep scanning if there are people around who might be able to sneak a tag on while you are there without you noticing.
Once you get in and start driving you can stop scanning unless your threat model includes people tagging your car in the middle of your trip.
I don’t deny that this behavior is bad, but the anti-Apple sentiment here is a bit strange given they provide mitigations unlike traditional gps tracking companies
However, it's possible to damage the speaker, so it becomes silent, without damaging the AirTag itself.
Depends on where you live. I live in a fairly affluent area, and everyone has iPhones.