You know the airports are open for multiple shifts per day, seven days a week, people take vacations, people get sick, and all that nasty variability that comes into place for staffing.

We’ve been understaffed on ATCs for years. Whatever the number that currently exists is not enough regardless of whatever back of the napkin math you can come up with. We just need more ATCs.

But that costs money and why would you spend money on redundancies in your system when you could cut costs and call it efficient.