How does that relate to AirTags (or similar devices, like Tile)? The companies that make these trackers aren't selling the data to anyone external, only displaying it to the person who bought the device.

I wasn't onboard at first, but I actually think that's a pretty reasonable take to have on it. Apple should be allowed to implement Find My, but only as an open standard that other manufacturers can implement so they can also have safety features. Simply notifying every iPhone isn't going to stop someone from putting it in a kid's backpack, tracking your vehicle, or any other obvious edge case. There are lots of solutions here, but all of them involve Apple tipping their hand: something they've vehemently opposed in the past.