What country were you in? I took two domestic flights within Japan last year, and it was crazy how similar it felt to boarding long-distance trains there. I showed my ticket, but did not need to present any form of personal ID, just the ticket. I checked two bags, then walked through a metal detector while passing my carry-on through a conveyor belt on the side.
When I take domestic flights within the US (between places like St. Louis, Denver, NYC, and LA), security takes far longer for several subtle reasons. Everyone has to show a government ID to a TSA employee (and get your photo checked against a database) before proceeding to the actual security lines. Then, most of the security lines use full-body scanners, not just metal detectors; some have moving parts and some don't, but they all require you to actually stand there for a second instead of just passing through. Every single person also has to take their shoes off before they go into those scanners, and you put your shoes through the same slower scanning system that the baggage goes through (which basically doubles the load and halves the bandwidth of the baggage conveyor belt).
In my experience, flying internationally out of/into the US (with both Japan and Canada as the other side) is no more security than flying domestically within the US. Which basically means we have full international-level security even for flying domestically here.
When I take domestic flights within the US (between places like St. Louis, Denver, NYC, and LA), security takes far longer for several subtle reasons. Everyone has to show a government ID to a TSA employee (and get your photo checked against a database) before proceeding to the actual security lines. Then, most of the security lines use full-body scanners, not just metal detectors; some have moving parts and some don't, but they all require you to actually stand there for a second instead of just passing through. Every single person also has to take their shoes off before they go into those scanners, and you put your shoes through the same slower scanning system that the baggage goes through (which basically doubles the load and halves the bandwidth of the baggage conveyor belt).
In my experience, flying internationally out of/into the US (with both Japan and Canada as the other side) is no more security than flying domestically within the US. Which basically means we have full international-level security even for flying domestically here.