I don’t think ATC currently has the capability of seeing who’s actually transmitting on the frequency.
If technology permits (probably by making a connection between the radios and the transponder), would it be helpful for controllers to be able to know the actual aircraft that’s transmitting on the frequency through their radar?
Does it also have the possibility of eliminating the requirement of saying the callsign after each transmission (might help in extremely busy airspaces)?
The visual aspect would be similar to how the “ident” feature works (like seeing a little “TX” when someone is transmitting).