Biden -- as part of the Obama administration -- couldn't even get a public option put into the ACA with the Democrats having a supermajority in both the House and Senate. What makes you think he'd be able to make wholesale changes to 401k? He may as well tell everyone he wants to give them a pony while he's dreaming.
The notion that Obama had 2 years of control of the House and Senate has been said before, and it's wrong.
Basically:
The Senate operates with a 60-vote requirement filibuster role. 100 Senate seats, so 60 votes are needed to bring legislation to the floor for a vote. On Jan 20th, 2009 the Dems had 57 seats, the Independents had 2 (Sanders and Lieberman caucusing with the Dems) for a total of
59; the Republicans had 41 seats.
But:
Ted Kennedy had a seizure during Obama's inaugural lunch and never returned to vote in the Senate. Al Franken was not officially seated until July 7, 2009. In April 2009, Rep. Arlen Spector became a Democrat. Kennedy died, having never returned, on August 25, 2009. His seat was filled temporarily on 9/24/2009 and gave the Senate Democrats 60 seats until February 4, 2010 when Scott Brown, a Republican, won Kennedy's Massachusetts seat.
So, Obama did "have control" of Congress - for 4 months. During that time the Affordable Care Act/Obamacare passed.