The alternative is to switch to IPv6. There is no requirement to offer any particular publicly reachable service on an IP address, a machine or device might be

The alternative is to switch to IPv6. There is no requirement to offer any particular publicly reachable service on an IP address, a machine or device might be completely firewalled off from directly communicating with the public internet, and it is still perfectly acceptable for it to have a globally unique IP address, so it is ultimately pointless to try and measure "the real utilization" using packets.