> but it won't (statistically) deliver higher returns.

Would you take a coin-flip where heads you double your net worth and tails you lose all your money and assets?

(Statistically) the expected outcome is zero, so it really shouldn't bother you either way, you could take the bet or not, it's the same if you go for it or if you don't.

In the real world, though, lowering your risk means reducing the chance of both winning the bet and losing it. For many people it's worth more to have less risk of randomly timing the market poorly, even though they have less chance of randomly timing it well.

Yes, over all investors the two decisions cancel out, but to the individual DCA can be worth lowering their risk.