The number of airplane hijackings was already in decline during the 90s and processes were already improving at airports around the world. Remembering that the TSA is a purely US production and doesn't represent the world, where most incidents happened. The world's airports have improved their processes and it's improved security a fair bit.

But ultimately the evidence is there, the TSA fails almost every test they're checked against by their own organisation. They're probably the least effective security force in the world, other than to frustrate people, they're good at that.

$8bn a year for an organisation who let through banned materials 70% of the time... https://www.forbes.com/sites/ellistalton/2019/01/28/is-the-tsa-really-necessary/