I remember interviewing for shopping centre chain (mall). They had this in 2018 already. It had an accuracy of +/- 1m but they had ways to normalise it to the layout of the store. Didn't require them to even be on the network just have their wifi on.
They not only used it to price their storefronts but also they also could tell their renters which parts of the store had higher traffic. Meaning they would know what sells better, where people go from which section. It's literally web analytics but irl.
This specific tech - WLAN sensing - tracks the signal disruptions caused by the water in our bodies. This makes it quite different than all previous techs that require the target to have a broadcasting device or other ping-able tracker. Reportedly, even pets are easily identifiable.
They not only used it to price their storefronts but also they also could tell their renters which parts of the store had higher traffic. Meaning they would know what sells better, where people go from which section. It's literally web analytics but irl.