This is because they don’t travel conventionally like you think they do. Some of these exotic craft are capable of banishing and appearing at another point in space. Is instantaneous and it’s possible thru quantum entanglement. You can travel faster than light using this method. Essentially these craft have the ability to cover extreme distances because the distances are non existent at the quantum lvl. Draw a line connecting two dots on a paper, now admire the distance or space between the dots. Take that paper and fold it so that the two dots meet at the same point. That is a visual representation of how these craft are capable of covering millions of light years distance in seconds.