>Will an air tag help the airline to identify you? That would be rather bad in a privacy sense
Apple is pretty careful about preventing that, unless you put the airtag in lost mode and enter your phone number.
There are some news stories about people who have had success getting their bags back using airtags. Yes, the airline does give them the runaround, but with a little persistence, and finding local phone numbers for the baggage office at the airport in question, people have had success.
I think it's just useful for extra peace of mind or information when your bag does go missing.
I see Air Canada has launched a feature on their app which actually tells you where your bag is (based on scanning the regular barcode tags). It's really just the info that the airline has, but I think they did that in response to so many people putting airtags in their luggage. Strangely, passengers like to know where their bag is when it goes missing, and quite often the airline's staff aren't that helpful.
I should say that the only time my bag went missing, it was simply because our connecting flight had been cancelled, and the rampies were slow getting the bags off, so we had to wait for an hour and it eventually came out. I only fly about 5 times a year, so I guess people who fly a lot might experience it more often (or, they just have carry-on bags).