Commenting here for the uneducated: in a 401k plan there are typically 2 fees. There’s the plan admin fee (typically 0.15-0.5%, higher if a smaller plan or lower if a bigger plan), and the expense ratio of the funds you’re invested in. This is the one you have control over because you can select funds that have higher expense ratios (usually actively managed funds that are usually a specific sector) or lower ones (passively managed Index funds). The target date funds are usually in the middle in terms of cost, so the fund companies want you in those by default because they typically have a better margin than the index funds. They’re harmless anyway and generally a safe choice.

Next time you look at your 401k allocation, check the expense ratios of the funds you’re holding. It might save you 0.25% annually to switch from say the Target date 2060 to a couple Index funds.