The scale of a sail needed to propel a giant cargo ship is really quite a bit different from what you might imagine on an old frigate, aka a “pirate ship.” Making a sail that large out of traditional materials is not feasible, and would require a ton of people to operate it. One of these monstrosities is staffed by probably less than 20 people, and labor is expensive, so this sort of computer operated sail can be both feasible and cost effective, whereas old school type sails were not