[GordonS]

Aside from the quality issues that others have already mentioned, I think that simply gaining traction for a new search engine is incredibly difficult - people typically use whatever is the default in their browser, or/and Google/Baidu/Yandex (which are surely the best known in their respective regions).

Consider DuckDuckGo, which sells itself on privacy, but after more than a decade has only 0.18% market share. Without the power to make it the default in an OS or browser, you'd have to have a really strong value proposition to convince people to switch.

[debatem1]

I don't think this is correct. For years, the #3 search query on Bing in the US was "Google", and globally it used to be a double-digit percentage of all Bing queries. That suggests to me that people with a default Bing search engine had learned in droves to click their way to the preferred engine regardless of what the default was, and did so without being technically skilled enough to change the default once and for all. I don't know how large a group the latter is, but it seems hard to argue that the two together are small.