> Boarding also always takes far longer than you'd imagine it should, mostly due to people being people. In principle you could board an airliner in a couple of minutes, but only with perfect behaviour from all passengers, so good luck with that.
I don't know why there isn't just a bunch of seats in the terminal laid out the same way as the plane. Sit there and wait, and then when it's time to board, the people at the end get on first, tada, everyone is boarded and we're not stopping each other from getting in.
It's because the overhead space is limited. Airlines have spent decades trashing, losing, and delaying checked luggage, so everyone tries to cram everything into the overheads. Since there's never enough room for everyone to do that, higher classes have to board first so they can. It would be nice if first class could at least be at the back so the line didn't completely stall in reverse order, but they also want to get out (the front) first, and you will never convince the other passengers to wait for that.
I don't know why there isn't just a bunch of seats in the terminal laid out the same way as the plane. Sit there and wait, and then when it's time to board, the people at the end get on first, tada, everyone is boarded and we're not stopping each other from getting in.