yeah but the same is pretty much true of a train or a bus, which don't require all of this TSA stuff. If you wanted to kill people for much lower effort you can just get in a car and run over pedestrians or something.
The justification for the TSA is that terrorist attacks like 9/11 could deal a disproportionate amount of damage compared to the effort needed to pull them off. But it's sort of a flawed premise because the 9/11 attacks relied on the element of surprise: the victims thought the attackers were pirates. Otherwise there's no way a couple of terrorists could fight off an entire plane with just box-cutters.
If you blow a hole in the side of a bus then the bus can come to a halt and the passengers disembark safely. Same story with a train.
If you blow a hole in the side of a plane, then no one can disembark until the plane lands, and the plane itself may simply disintegrate mid-air, killing everyone on board.
Same story if you fill the bus or train with toxic gas, or try to start shooting, or literally any other form of attempted mass casualty attack. Planes are uniquely different to all other modes of transportation because you cannot disembark them quickly and the default failure mode is everybody dies.
The justification for the TSA is that terrorist attacks like 9/11 could deal a disproportionate amount of damage compared to the effort needed to pull them off. But it's sort of a flawed premise because the 9/11 attacks relied on the element of surprise: the victims thought the attackers were pirates. Otherwise there's no way a couple of terrorists could fight off an entire plane with just box-cutters.