But they only have high market share because people want to use Google instead of the competitors. Many consumers switch their search engine to Google when presented with other defaults. Because Google search works the best and people know that.
The aggressive marketing of Chrome on Google Search website to users using other browsers was a significant part of Chrome adoption success.
And no - some people didn't willingly and consciously switched to their search engine. It was pushed down their throats by browser vendors being paid-off by Google for setting it as the default one. Mozilla has overwritten user-changed search engine setting in Firefox with several updates.
Non tech-savvy users simply accept changes made in software they use.
Nowadays using Google Search is, since they pivoted from from being a "search company" to "adtech company" which resulted in the degradation of Google Search quality.
"Engines like Bing" is an ambiguous term. There are better options than Bing.