Increasing staffing doesn’t help. It’s a basic queuing problem. You would have to increase the size of the airports along with the staff.. meaning perhaps hundreds of separate lanes, hundreds of separate X-ray machines and belts etc etc.
At my local airport, all security lanes except for one for precheck, are well staffed and move as fast as the passengers allow. The space is already used maximally, however lines are exceedingly long. Switching the precheck lane to regular would have almost no effect on wait times.
Queuing theory is rather complex.