You can do a lot with residential IP addresses and home wifi/router connections, since very often a typical DHCP residential internet customer does not change I

You can do a lot with residential IP addresses and home wifi/router connections, since very often a typical DHCP residential internet customer does not change IPs very much. Or at all. DHCP renewal request often comes back for the same IP. Or only changes IPs to another address in a very small /24 to /26 sized block that's assigned to a router in one very specific geographic area. Or you have a case like a bunch of customers all behind one cgnat exit point to the internet that also does not change in geographic scope/scale of how many cgnatted customers are behind it. As commonly seen on LTE networks. Even if you have not granted GPS location permission to an app there is a very high likelihood that other people in the same small netblock have, which greatly improves a third party's correlation of netblock-to-lat/long.