From a user point of view, a search engine’s job is to link you away from the search engine, so how does a search engine measure engagement? Is it time on page or maybe number of searches performed? When you don’t have viable competitors both of those are improved by worse search results. Even number of ads clicked would be improved with worse search results because ads don’t have as much competition for your attention when there are no relevant results on the page.
> From a user point of view, a search engine’s job is to link you away from the search engine
That hasn't been true for a long while.
Users are there for an answer to their query, not to be directed anywhere. Frequently this comes in the form of search vertical response that doesn't lead the user anywhere.
From Google's point of view, you want the user where you can show them ads, full stop. Google does not exist to provide you with answers to your queries, it exists to make money for shareholders.
> When you don’t have viable competitors both of those are improved by worse search results.
I don't think "worse search results" is the way to think of it. From G's point of view they're better because they make them more money.