Wmc, home IP addresses normally change whenever a router is restarted – easy to get round. And people use VPNs (I do) which mask the users real IP address.
The reality is that you have to turn your equipment off for a good few hours to force an ip change, try it.
Domestic VPN usage is so small it is not an issue, also people tend to find a geolocation and stick to it, it does not affect our work. Trust me.