One notable change is: reinforced cockpit doors that can't be forced open from the outside easily. Good luck hijacking with that.
But another notable change is that plane crews and passengers all understand now that plane hijacking is a life or death situation, and would fight hijackers to the bitter end.
Which is what happened on the very day of 9/11, on Flight 93.
How long do you think it’s going to be before a pilot opens the door if a hijacker starts shooting people?
Airport security is by far not just in America with the only exception in my experience is that other airports don’t make you take your shoes off and some allow liquids in carryon
There also isn't room to get away from angry passengers. They're probably going to overwhelm terrorists with guns relatively quickly.
I would book a first class flight in the first seat in front of the plane. Make all of the first class passenger - fewer of them, probably wealthier business travelers who don’t think they are Rambo - move to the back of the cabin.
The aisle would be the perfect kill zone. I watched a documentary and they said SWAT training for taking over a plane from terrorist they know that whoever goes in first is likely to get shot.
No you don’t pay for TSA out of taxpayer money. The airlines do bu adding a cost to your ticket.
I expressed no opinion on the TSA.