I'm a good example of having a pension & an 401K.
The pension covers a majority of my expenses and the 401K allows for more toys.
I used the 401K for a new custom boat & trailer, paid off my mortgage, bought a new truck { taken out around 150K over the last 7 years }. And still have enough left to keep me comfortable into old age.
And because of all this I can wait until 70 yrs to collect SS. { the maximum possible amount allowed }