Defined Contribution (DC) Plans are not "better"  than Defined Benefit (DB) Plans.  The markets cannot be trusted to work at a retail level for the general public (small time investors) needs in a DC world  - surely the last forty years of stock market chaos and deregulation have proven this over and over.
One needs to think carefully about the purpose of capitalism.  If you believe its to serve society,  then it must be held in check to prevent oligarchic power from from seizing too much of the capital at the top and giving birdfeed to the masses of workers (DC plans).   DB plans , properly regulated are the glue that holds the social compact together in a modern liberal democratic society.   The discipline required to create a broad opportunity-based society of general prosperity demands we design economics for DB systems.    The failure of DC systems to provide enough retirement income is a reason the minimum annual income idea is back in vogue