Not surprising. For several days now TikTok has left the information of 700 million of their users available via an open S3 bucket. It is online now at this very moment and includes IDFAs from Apple as well as interestingly, although I bet American companies do this to, the MAC Addresses. This is significant because my understanding is that Apple rotates / randomizes the MAC address because those can be used to, quite effectively, track individuals anywhere in the world (I would say it is better than GPS often at this point, especially indoors). Storage is cheap so maybe everyone stores them these days, or perhaps someone has found how to guess the rotation pattern (completely unproven theory that is likely wrong but only thing I can think of).

The coverage that Skyhook claims to have for instance is extraordinary considering this is totally reliant on Wifi points and cell towers: https://www.skyhook.com/Coverage-Map