We made flights more secure with the better door to the cockpit. The TSA part is equally effective as a metal detector is. It wouldn’t be less secure to not do the enhanced screening the TSA does. It would mean several companies lose out on massive contracts for that fancy equipment, which is why it won’t happen.
It’s also just math working. The older millennials should be millionaires or close to it in order to be on track for retirement. A 401k is going to make people look wealthier than a pension.