While I agree that the US is stricter, the EU has gotten strict as well. There are millimeter-wave scanners in many airports (usually mandatory with an opt-out pat-down, but in some airports you have a chance to just go through the metal detectors), sometimes they make you take your shoes off, X-raying takes ages. The US is stricter only in the sense that the TSA is everywhere all the time, whereas in Europe it's only some places some of the time. At least in Europe you don't have some highschool dropout rifle through your luggage and leave your suitcase open, though (that's happened to me in the US).

It used to be that you'd go through a metal detector and be done with it, and that's still the way it is in, for example, Greece. My local airport (second largest in the country, but still no SFO) gets you from the entrance to the gate in less than ten minutes.

I don't know why we've accepted this bullshit. It's not as if some malicious actor couldn't just hit a train or bus instead and kill just as many people, yet we accept all this hassle and invasion of privacy for exactly zero benefit.