> I’m honestly not sure why springs are common at all in this application.
Properly adjusted springs effectively cancel out the weight of the door. This makes it easy to open and close with and without an opener, and greatly limits the danger of a door falling closed under it's own weight, which can seriously hurt someone.
One of my garage door springs snapped unexpectedly while my housemate was opening the garage door. I'm glad nobody was under the door at the time since it slammed so hard it put a bend in the bottom section.
