The whole thing about queues at airports is a question of lies, damn lies, and statistics.
The airport owners want to quote short queues for everything. So they measure the queue for, say, security, or passport control, once every hour. They do this every hour. Including those times when no-one is going through the airport.
So one awful queue at 7.30 am is averaged out by zero queues at 01.30 and etc.