That's a weirdly specific requirement though... 3D Printing can also print shapes and objects that aren't possible with traditional manufacturing techniques. Not every process can be used for every object.
I've made a number of outdoor enclosures for electronics projects on my 3D printer. One of the killer features is that you can make vents that take curved paths through the walls of an enclosure. This, when done properly, can prevent most water ingress flawlessly, but allow a surprisingly large amount of airflow
