Why use a 529 instead of just a regular brokerage account for college?

The main advantage is taxes. In a 529, your investments grow tax-deferred and withdrawals for qualified education expenses are completely tax-free — no capital-gains tax on years of growth. A taxable brokerage account, by contrast, generates taxable dividends along the way and capital-gains tax when you sell. Many states also give an income-tax deduction for 529 contributions, which a brokerage doesn't. The 529 also gets favorable financial-aid treatment as a parent asset (around 5.6% versus the full value of some other accounts). The trade-off is flexibility: a brokerage account can fund anything, while a 529 is for education (with a 10% penalty on earnings for non-qualified withdrawals). For dedicated college money, the tax savings usually make the 529 the clear winner.