Doesn't actually help at all because the BGP announced prefix of your IP can still be tracerouted. You won't be physically far from it.
Say if your ISP announces 125.15.18.0/17 and you're in 125.15.29.145, a traceroute will still yield a pretty good approximation of where you're at. The last hop ping is really quite immaterial here.
I understand that was the initial question. I am saying that is a fools errand. Anyone with a few VPSes, a calculator, and a map can do this. It isn't just ipinfo.io doing this. There are a lot of ip geolocation services.
And if you don't respond to pings, a traceroute can still be used to find the hop before yours, which will almost certainly achieve the same result for geolocation purposes.