It's security theater through and through.

Apart from the obvious failings of these checks, think about what kind of damage a single backpack of explosives can do to a packed airport during holiday season. You can literally put a ton of explosives on one of those trolleys, roll it into the waiting area and kill 200 people easily. No security whatsoever involved.

Reality is, most security measures are designed to keep the illusion of control. Nothing more. Penetration testers show again and again that you can easily circumvent practically all barriers or measures.