[femto]

Latency is an active research area and a driver for updating wireless networks. You won't see the results in the current 5G roll outs, which concentrate on eMBB, but the research is feeding into the future URLLC (Ultra-Reliable Low-Latency Communications), which is a 5G protocol aimed at machine-to-machine communications.

Beyond URLLC are protocols aimed at replacing wires in "serious" industrial control systems: things like real time control of grid switchgear and heavy machinery, so you might not see it on your phone. Latencies of the order of microseconds have been demonstrated in recent years and the stretch goal is about 200ns.