This is 100% true. Mainstream 401k fees are out of control. I don't know how much is opportunism and how much is regulatory burden, but parity to wealthfront or anything else retail would be fucking miraculous.
It would be amazing if Congress eliminated 401ks, and brought over the employer contribution feature as well as the increased participant contribution limits to IRAs. The only reason asset managers get away with charging such outrageous fees is because you're a captive audience with your 401k.
Make them portable such that an IRA is and watch the fees fall.
To put up something concrete, my last large employer had a 401k plan where the cheapest fund we had access to (PLFMX) had an expense ratio of 0.72%. That's in addition to account-level management fees, which I think were ~0.8%.
Make them portable such that an IRA is and watch the fees fall.