This isn’t accurate. The amount of data available on a DOCSIS network is incredible. Per modem SNR, power levels, preEq data, etc. If the data is used properly it cans find a loose screw on a tap or a damaged cable down the the foot.

That being said impulse noise is one of the harder things to track down. If the modern tools don’t work most MSOs would end up doing the “unplug a leg and see if the SNR gets better” method until they found the offending house.