I think that's entering an area of ad ethics. Yet, its an ethical violation that companies like Google make today. If I search for "Wealthfront", I get an ad for Wealthfront, Betterment, and TDAmeritrade, in that order, before an organic result for Wealthfront. If Wealthfront didn't pay up, even though it is _obvious_ what I am looking for, the result I am looking would be buried. That's a protection racket.
Rank-based advertising, like in search results, is fundamentally unethical. To do it ethically would require perfect comprehension of what the searcher is seeking, so that you can prioritize organic, helpful results. Google never prioritizes organic results.
If I search for "Wealthfront", how likely is it that I don't know they exist and need help finding their homepage, and how likely is it that I want to read about the type of service they offer?
What? It's not a protection racket. Google is a private enterprise who is free to show whatever content they like on their page. Not showing your site is not illegal, nor is it unethical. A protection racket involves some illegal compulsion to pay for the protection. That's what makes it illegal.
I don't think you understand what a monopoly entails. Having a large marketshare is simply not the only qualifier. It's also not remotely anti-competitive. That's just not what that word means.
Rank-based advertising, like in search results, is fundamentally unethical. To do it ethically would require perfect comprehension of what the searcher is seeking, so that you can prioritize organic, helpful results. Google never prioritizes organic results.