It’s IMO worse than useless as terrorists can more easily kill people at the airport lines than destroying an aircraft. Holiday rush + luggage filled with even gunpowder and metal would make a huge statement that that everything we did was worse than useless.

I was honestly expecting exactly that kind of follow up attack for years.

The main purpose of airport security is not to prevent people from blowing up planes (although that’s an important secondary purpose) — it’s to prevent hijackings. Read about hijackings in the 60s before airport security; they were extremely common and disruptive.

Yes and no. Airport security showed up after US hijackings had already peaked, based on timing it seems the Federal Air Marshal Service service may have had a larger impact. The airport screenings are really an outgrowth of a Supreme Court case making such in depth screenings legal.

Also it was relatively frequent but not that serious in the late 1960’s. The first US fatality from aircraft high jacking didn’t occur until 1970.

Attacking airports has also happened multiple times including a 2002 incident in LA and even quite deadly attacks: https://en.wikipedia.org/wiki/Lod_Airport_massacre

why is a hijacking worse?

You can fly the plane into a building and kill thousands of people (source: 9/11)

As opposed to killing hundreds.

But can you really? The pilot doors are now locked from the inside and impenetrable.

That's a fair question, but I was answering why hijacking is worse, which implies that a hijacking can happen.

I'm not saying that the current TSA theater is the most efficient way to stop hijackings.

9/11 probably killed millions of people if you consider the destabilizing effect on geopolitics.

Why would they spend more money to make it faster when they can just charge people for the faster precheck line?

> he government could hire 10x the number of agents to minimize lines without changing their budget by more than a rounding error, but they don’t care to.

Don't be ridiculous. At every airport and terminal??

And then how many extra people standing around doing nothing when it is a quiet period??

Roughly 10x as many as are standing around doing nothing now. Take a look at security from the raised view provided at Denver International. You’ll see at any given time roughly 1/2 the agents standing around chatting with one another.