

I haven’t looked it up but I would bet you it’s due to fatigue limits. They probably use aluminum a lot which always fatigues no matter how light the stress (a bit like me tbh…) so anything made from aluminum gets retired after a set time period.
The same is true for jets. Each flight expands and contracts the airframe since it’s a pressure vessel, and the wings can deflect a large amount too.







They also walk around on their middle fingers so they’re literally flipping the world off with all 4 limbs from the day they were born.