It's actually a pretty cool feature (when it works as intended), I once saw this dialog when visiting a friend who also had a pair of Airpods and we mixed them by accident.

I much prefer that when I connect my gf's headphones to my phone, or vice versa, or anything to anything, they just work. There is no excuse for this. It's ridiculous to even contemplate really.

How come over the last idk 40 years since portable electronics with headphones have been around, I never had any such calamity that my headphones got confused with someone else's? Oh right, they weren't $200 for no reason for one thing so who tf cared if it ever did happen, and there were 6000 different companies and models and styles instead of everyone in the world having the exact same thing.