These systems (brakes, airbags) have robust and trivial design, to eliminate any tendency to break on their own. As a side effect, replacing a replaceable airba

These systems (brakes, airbags) have robust and trivial design, to eliminate any tendency to break on their own. As a side effect, replacing a replaceable airbag is something a layperson can do with a little to none room for screwup, unlike for example a repair of a non safety critical engine, where there is a lot of that room.