The airtag will start making sound after being separated from its owner for 3 days. That at least gives you the opportunity to locate and disable the airtag.
Took all of 3 minutes. Super convenient.
But for a casual malicious user, airtags open up whole new worlds of abuse.
I think it's also important to consider that Apple getting into this market does a lot to normalize use of trackers and also make them commercially ubiquitous.