As somebody who has jumped out of perfectly good airplanes at serious altitude, let me draw another parallel.

Jumping out of an airplane with a parachute from height is dangerous. Landing hurts. I jumped in the military with critical safety gear and some training, but it was still not safe. Imagine jumping off a one-story roof wearing combat boots and a heavy back pack. That's what parachuting feels like. If you don't drop and roll properly, you're going to be injured. (Flow control parachutes that allow for easy landings are a different story; they require unusually high levels of training and skill.)

Each of the three times my training unit jumped, somebody got hurt, from sprained ankles to fractures.

But nobody died or ended up with permanent injuries.

I think parallels to masks in my example are important. To jump from an aircraft with a parachute and not get injured, you have to have the proper training, and you have to execute it properly. Even then, you might get hurt. But that doesn't mean parachutes don't work. It means they aren't perfect.

Just like masks.