This has actually been true since at least 2013, as long as you were optimising for something that made you money. If you're optimising for a proxy objective,

This has actually been true since at least 2013, as long as you were optimising for something that made you money. If you're optimising for a proxy objective, more granular targeting can make sense (if you have more information about your customers), but if you can just make money from website conversions or in-app purchases, you're better off letting the algorithm do its thing. (The magic is driven not by incredible engineers but by more people to show the ad to enabling the only people who see it to have high expected conversion rates. This is perhaps the real dirty secret of internet advertising, in that they are predominantly platforms for showing ads to people who were probably going to convert anyway).