Privacy advocates got access to Locate X, a phone tracking tool which multiple U.S. agencies have bought access to, and showed me and other journalists exactly what it was capable of. Tracking a phone from one state to another to an abortion clinic. Multiple places of worship. A school. Following a likely juror to a residence. And all of this tracking is possible without a warrant, and instead just a few clicks of a mouse.
The problem is turning off wifi doesn’t actually turn off the wifi, it just stops a subset of packets being broadcast and won’t trasmit any data you want it to send. Among other things this is how ‘find my device’ works with the wifi and bluetooth “off”. They’re actually on.
You can turn this wifi and bt scanning/‘location accuracy improvements’ off though, at least on android. It’s tucked away in the settings but once it’s done, it’s done.