Humans are great at snatching defeat from the jaws of victory …
ADS-B or something like it is 30 years too late. We have had GPS for maybe that long. It’s possibilities were ignored for many years.
And now how is it normally implemented? Keep the pilots eyes inside the cockpit to watch a display instead of outside the cockpit, where they belong. Audio warnings should be part of every ADS-B installation with advise on where possible intersections are, and suggestions on actions to avoid a collision.