Airtags seem unnecessary until you wish you had them.
My wife recently had her luggage lost by an Airline as we flew overseas for 30 days.
It was lost for the entire trip.
The first thing we did after buying a replacement luggage was buy airtags for both our bags.
My friend's private office / coworking in Lisbon got burglared at night
They took his Apple Studio Display of about $4000, he even made a custom travel case for it which had an Airtag on it, the criminals were smart and packed it in his case and took it
He had an Airtag on it so tracked it, he found it in a warehouse south of Lisbon
He reported it to Portuguese police, and showed where it was with the Airtag, they said they couldn't do anything because it was inside a building and by law they could not enter private property to recover it
If they can't then what is police even for?