Microsoft entered negotiations to sell Bing to Apple in 2020
After losing default search status to Google in 2017, Microsoft discussed selling Bing to Apple in 2020, but talks fizzled out.

Bing could have been sold to Apple
The Google antitrust bench trial continues to reveal details about its relationship with Apple and how it affected other companies. Microsoft executives say Apple used Bing as a bargaining chip, but more details have emerged from anonymous sources.
According to a report from Bloomberg, Microsoft floated the idea to sell Bing to Apple in 2020. Negotiations were made with Apple SVP Eddy Cue, but they apparently never left the exploratory phase.
Bing had been the default search engine on Apple products from 2013 to 2017, but Google took over from there. The revenue share deal with Apple eliminated Bing's ability to compete, even when Microsoft made drastic offers.
Eddy Cue was on the stand on Tuesday, and he said Google was the only option for Apple because it was, and is, the best search engine option. The company also isn't interested in creating its own search engine to compete with Google, which explains why Apple avoided buying Bing.
Apple and Google's financial relationship is under a lot of scrutiny from the US Department of Justice. It's part of a greater antitrust investigation meant to determine if Google is using its money and power to keep the competition from getting a foothold.
Read on AppleInsider

Comments
Apple won't make a Google search rival, says Eddy Cue (appleinsider.com)
And I don't think Google would have issues with the "loyal" Apple user base. If you noticed, Apple loyal users are more focused in hardware (Mac, iPad, Apple Watch, iPhone). But software and services is a different story. Most Apple users have Gmail accounts, and don't use iCloud accounts. MS Office and Google Workspace usage in Apple devices is ahead compared to the Apple suite of apps, even though they are free. And even mobile apps and TV services like Google Maps, Spotify, Netflix and Disney+ are more popular than Apple alternatives. I don't think an Apple search engine will make any difference to Google.
That's not a great example considering the thread topic. All competing browsers are knee-capped by Apple, so any advantages are muted. If it were Google doing so, it would certainly be subject to a solid antitrust case.
Regarding Chrome, I'm not sure if it's market share in iOS less than 5%, since the article you posted is from 2016, and the stats are only from US government websites. If that's the case today, then Google is right to think that the defaults are important, so they pay Apple billions to make Google Search the default engine. IMO, that could make sense.
https://www.justinobeirne.com/how-many-people-use-google-maps-compared-to-apple-maps
https://www.nearmedia.co/apple-maps-momentum-google-threads-ai-needle-location-sharing/
You are forgetting to apply the "napkin math". Apple Map is only on iOS. There's only about 1.4B iOS devices. If 500M owners of those devices are using Apple Map, Then about 38% of iOS users are using Apple Map. The consensus is that it is higher than that in the US, where iPhone is now over 50% of the market. And the US is a very profitable market for targeted ads. Which is how Google derive their revenue with their "free" Google Map app. Losing 38% of iOS map users to Apple Map is not insignificant. (Discounting that many might be using both map services.)