Mass reduction whilst maintain strength and reliability and serviceability has been going on for many years.
These factors always peak in times of conflict. Who can out manoeuver the opposition, who can take more hits, who uses less fuel (time in air), who can be quickly put back on the flight list after combat damage.
Mechanical design has become very complex in these times. Strength is only 1 factor ot many 100s of others. Crumple / progressive deceleration, mass reduction, reparability and durability.
Now I suspect that manufacturers can limit durability to 10 or 15 years. (call it acceptable design life). Having capped this threshold they can move on to other factors.
