The problem is you have to allow extra time in case something has gone wrong. I waited two hours in a queue at O'Hare just to get through security - thankfully I had allowed three hours.
Compare that to anywhere in Australia where you can be sure security won't take more than 10 minutes - you can arrive at the airport with 45 minutes before your flight and still be waiting 20 minutes after you check in and pass security before you board.
Compare that to anywhere in Australia where you can be sure security won't take more than 10 minutes - you can arrive at the airport with 45 minutes before your flight and still be waiting 20 minutes after you check in and pass security before you board.