Wealth accumulates for the 70+ crowd faster than the population growth for the 70+ crowd.
While this does not necessarily suggest "inequity," it does indicate "increased concentration" of wealth for the 70+ crowd.
Wealth in pension funds vs. wealth in 401(k)? That comes down to control. The wealth in pension funds meant to benefit the 70+crowd is not controlled by the 70+ crowd. The wealth in 401(k) accounts of the 70+ crowd is controlled by the 70+ crowd. Is one "better" than the other? That's a whole other discussion.