I'd frame it more that Google is incentivised to show you the results which are most lucrative for them to display, rather than the ones which are most beneficial for you to see.

Incentives. Which is why platforms (such as search) should never be allowed to be in the same company with things built on top of them (such as ads), if the combined company is significant for an important market.

We used to know better, Standard Oil vertical integration was dismantled.