It is security theater but it's set up that way for good reason. The long winding lines are intended to let cameras get good images of you from multiple angles

It is security theater but it's set up that way for good reason. The long winding lines are intended to let cameras get good images of you from multiple angles and have time to run those images through a database. Anyone flagged is standing for several minutes in a heavily guarded area with no electronics, no shoes, not even a belt: they're in no position to run, hide, or fight.