Forget "systems". It all comes down to passengers not preparing themselves in advance, same as security lines. Prior to reaching the aircraft I have taken out anything I need whilst seated. When I reach my seat I place those items on the seat and immediately proceed to place bag (and coat if applicable) in the overhead locker and taking my seat without delay. Same goes with security, I prepare as much as possible in advance whilst I watch people wait until actually at the belt before starting the process.