Not as simple:
1) You need to implement it for very small airplanes too, which is far from easy. In the Linate air disaster a small Cessna Citation invaded the runtime due to fog and misscomunication.
2) You need to implement it for ground vehicles too, as in the LATAM example it was a fire truck that invaded the runtime.
3) You need A LOT of infrastructural update.
4) Even if you had computers talking to computers, this may still be far from enough to avoid collisions, as those mistakes are often a matter of seconds (as in the both accidents quoted before).
5) Automation brings its own issues. One of them is complacency where attention levels unavoidably get lower as reliance on automation increases. In turn complacency can make runways more prone to such incidents in case of malfunctions/bugs.