The right question is “How can I make this area NOT UGLY?”
Think Stonehenge. Think Woodland Garden. Your boxes are like stone forms. Add more stone forms to give them context.
A rock garden can give glorious color and year-round interest for full sun areas. If you have trees and shrubs, add a couple large rocks and space out a few more shrubs with groundcovers.
In most cases we screen unwanted views by distraction rather than completely hiding them. Put your utilities in a beautiful context and work with what you have. Your technicians will appreciate you and everyone will think you are smart! Life if good.