The ATC is engineered to work automatically. If a breakdown

The ATC is engineered to work automatically. If a breakdown
happens to the main data computer, the back up system will take
over. The ATC is conducted from the air control tower, which is
dubbed as the nerve center of an airport. All activities from
take off, landing and taxi are controlled from the tower.

In the incident at the Soekarno-Hatta International Airport
breakdown, the back up system did not work. Delaying an airplane
will only result on the domino effect for all flight schedule.