Other replies have been excellent. A couple of more points.

You assume 1.6% in expenses for the mutual funds in your Plan. That seems quite high. You dont however factor in any investment expense in investing outside the Plan. Even low cost index funds have expenses.

You mention you don't control the investments in the 401k. Most 401k Plans provider a diversified menu of funds to select from and the participant allocates their money among these funds.

You say the money will be tied up until age 67. Many Plans allow for in service distributions at age 59 1/2. There are other instances where you can access the money penalty free even earlier. (age 55 or older and terminate employment, or 72t distributions).