What do you mean by "trust that their 401k is correctly managed"? Those 401(k) plans are self managed. In most plans the investment selection defaults to a low-cost retirement date fund. There's no one to trust.
So you are working on the assumption that LifePath or similar ETFs are going to be correctly managed for their cohort (shifting into safer investments as the retirement date approaches).
Historically, it looks like the risk of being in stocks as you approach retirement is pretty low. Let’s say you planned on retiring in 2009 at age 65. 2009 hits, stocks fall 50%… if you just continued working for 2-3 more years, your retirement account would be back at fresh all time highs AND you’d be collecting a larger SS paycheck each month when you retired at 67-68. Not exactly tragic.
I'm no expert, but I thought that was one of the big problems with recessions.