Trade vessels have superior speed. They have Battleship scanners. They have the firepower to distract bombers enough and they make any fighter look like a clown with the .87 guns. Activity is low enough to make a lot of runs unchallenged.
Many things help traders. And I did not list them all.
However some pirates always find their way. My call is pirating in transports.
QQ is pointless but I believe the balance struggle between traders and pirates will go on for eternity. It's just the nature of it.