You only need ~1/10000th of Google's revenue to be a financially successful startup. 1/1000th and you'll have a great business, and at 1/100th you'll be somewhere between a unicorn and a decacorn.
A company with an objectively superior search engine could make even more money with ads so now you’re back to the beginning
An “objectively superior” search engine, from an end user’s perspective, might have to make engineering choices that come at the expense of ad revenue.
But we’re all just talking hypothesis, it’d be cool to see someone launch a startup to get some answers.