3000 miles is still a relevant clue if the target users continental location isn't already known. Additionally even in this very weak form it provides useful data for anti-fraud metrics. For example by payment processors like Paypal that may use [total latency minus ping latency] to feed a metric indicating possible proxy use.

But I also assumed an investigative organization that took the idea further would use the latency information with a map of latencies between major internet exchanges. This would increase accuracy and usefulness, though still the entire idea only works to provide indefinite clues