Um... that's not quite right. Here's the thing, if you earn $100k and invest it in pre-tax (401k) or post-tax (Roth), and you pay the same tax rate throughout, then with both investment strategies you will end up with EXACTLY the same amount of money. The only benefit of a Roth is if you assume you have a higher tax rate in the future when you want to pull it out. If your tax rate is the same both now and in the future, then Roth and 401k are equivalent investment vehicles. If you don't believe me, do the math yourself.

Slightly more detail. The reason this is true is that return on your investment and the tax are both percentages of your base investment and the math doesn't care which order you multiply one versus the other. So let's say you make a 500% return on your investment and the tax rate is 30%

$100k * (0.7 tax rate) * (5 ROI) = $350k Tax first Roth

$100k * (5 ROI) * (0.7 tax rate) = $350k Tax after 401k

So the take-aways are:

401k wins if you have company matching. ALWAYS invest at least up to company matching because that's free money.

Roth wins if your tax rate in the future is higher than now. (this is not necessarily a good bet because your tax rate will probably be lower once you're retired.)