That is how locations are transmitted for Find My Phone/Device, and how relative close-by positioning works for AirTags and similar, but it's not used to determine absolute locations as far as I know. It would certainly be cool if it did that though.
3GPP Release 16 started the UWB location and position scope while Release 17 finalized the 5GC capability. Perhaps more work is being done there, I haven't been tracking it closely lately.
You might be thinking of https://en.wikipedia.org/wiki/Differential_GPS.