The TSA is something that shouldn’t exist in its current form. They very often fail their audit checks and normalize invading your privacy to an extreme degree like body scanners and pat downs. If water bottles are considered potentially explosive then why dump them on a bin next to a line of people where they can go off? This is low grade security theater that inconveniences passengers at best.
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.
The goal is not to stop the people in the queue being attacked, its to stop someone boarding a plane with the means to hijack it
They fail gloriously at at that too.
Whenever they get tested the red teams manage to smuggle in everything needed to hijiack a plane plus a kitchen sink.
The few times that terrorists tried to board planes, they made it through security and were caught by other passengers.