[sandworm101]

I am old enough, but arriving 20min before a flight was never really a thing. You could in theory arrive that way, but you were running a risk. Any delay in security, a delay in the bus system, or just bad luck with an irrate customs person could always delay you a few minutes too long. And if you werent even checked in 20min before your flight you had a very good chance of being bumped off the flight for someone on standby. There was also zero chance of any checked bags making it onto your flight unless you were checking in at least an hour before travel.