We only ask for location permission on Android devices, not on iOS devices. This is because Android/Google requires that apps requesting access to Bluetooth also obtain location permission, as Bluetooth can be used to derive location information when combined with beacons in fixed locations.
For more information, please see: https://developer.android.com/guide/topics/connectivity/bluetooth
In short, we do ask for location permissions because we need Bluetooth permissions. But TraceTogether does not collect or use location data on Android.