New employees by themselves aren't the problem, and can be trained and eventually get sufficient experience by working in an environment where the people around

New employees by themselves aren't the problem, and can be trained and eventually get sufficient experience by working in an environment where the people around them know what they are doing. But if you don't train them, and not enough people around them know what they are doing, they can never get the experience needed. Boeing just cheaped out, didn't retain, didn't train.