These trackers work by connecting to nearby phones, with the phone supplying GPS information and uploading it via its cell connection. So a Tile tracker will only get its location updated if someone with the Tile app is nearby, and since Tile users are relatively rare the tracking is only reliable in very busy places.
Apple and now Google trackers on the other hand build this functionality into the OS (or Google's near-OS bundle for Android), so if basically any phone comes within range of the tracker it will provide a location update.
> How does the tracking network size affect functionality?
Ability to actually find lost items. AirTags are so successful (in the US) because of the ubiquity of iPhones which are, effectively, constantly reporting on the location of detected devices. A smaller network of listening/reporting devices will not be as effective unless it happens to be very popular right in the area the device was lost.
The devices don't have any GPS. Instead, they have a unique ID that phones see, and report their location to Apple/Google/Tile. If the network is bigger/denser, then your devices is more likely to be detected, and detected more often.
