Bluetooth beacons can track your location from 50 meters away with an accuracy of inches
"Beacons are placed at airports, malls, subways, buses, taxis, sporting arenas, gyms, hotels, hospitals, music festivals, cinemas and museums, and even on billboards."
"Companies like Reveal Mobile collect data from software development kits inside hundreds of frequently used apps. In the United States, another company, inMarket, covers 38 percent of millennial moms and about one-quarter of all smartphones, and tracks 50 million people each month. Other players have similar reach." https://www.nytimes.com/interactive/2019/06/14/opinion/bluetooth-wireless-tracking-privacy.html
Android phones with Google services track users location and send that information to Google if bluetooth scanning is enabled even when bluetooth is turned off. You can turn off bluetooth scanning under location settings.