Are robo-advisor fees worth it compared to just buying index funds myself?

It depends on how much you value automation. A typical robo-advisor charges about 0.25 percent a year on top of the underlying ETF fees, so on a 100,000 dollar portfolio that's roughly 250 dollars annually. For that you get automatic rebalancing, tax-loss harvesting in taxable accounts, and a done-for-you portfolio. If you'd otherwise procrastinate, panic-sell, or never rebalance, the fee can easily pay for itself in better behavior. But if you're comfortable buying a single target-date fund or a simple three-fund portfolio and leaving it alone, you can capture nearly identical returns for close to zero extra cost. The math favors DIY as your balance grows, since the percentage fee applies to a larger number. Weigh the fee against your honest likelihood of managing it yourself.