I did a lot of research into the state of Ultra Wideband (UWB) during the early 00s. It utilized time of flight and a wide band of frequencies to do similar things. There were 2-3 major, well funded companies pursuing the tech at the time.

Interestingly those companies never made it commercially, I suppose because the cost of computation was prohibitive and they required special antenna.

It is very exciting that the technology can now be done in a cost effective manner.

Most interesting though is how easily and effective ML was in adding functionality to this implementation. Very cool.