[aidenn0]

> You reduce your taxable income and the money doesn't pay capital gains when you pull it out.

You do pay income tax on it when you pull it out though. Whether or not you come out ahead depends at least partially on your marginal tax rates before and after retirement.

[Izikiel43]

If you are in the situation where you can max your 401k, it's likely your income during retirement and the associated taxes will be lower.

[aidenn0]

But it does not follow that your marginal tax rate will be lower; there's policy uncertainty there.