That doesn't work with all transponders, right? Many private or military craft don't work with that system.
https://www.twz.com/news-features/heres-what-air-traffic-col...
So there's already tracking on a map that's available to the pilots. During landing, pilots are looking outside and not glued to their instruments.
The real issue is trying to cram too much aircraft in such a small space and time.