And you could bring a drink and keep your shoes on and nobody was swabbing and bomb testing your toothpaste. The cumulative effect made the lines move about four times faster.
Edit: I think there's also a lot of inefficiency. So often I see a huge line, half the equipment sitting idle, and half the TSA agents standing around talking to each other. I don't remember that sort of thing in the before times. Maybe because the security people were employed by private companies motivated to get their money's worth.