Notably the claim is being made that the search market is being monopolized, not that there is a bundle at issue. If the government thinks there’s a bundle here they can make that claim.
The government is claiming that the search market is being monopolized, not by having the best results, but by paying $45 billion dollars/year to various browser suppliers to make Google the default browser. That's the illegal act.
> "Essentially, Google has bought up all of the shelf space where search is placed in front of consumers, which is to say browsers and phones. This behavior is very similar to what Microsoft did in the 1990s, when it bundled its browser with its operating system, and signed deals with ISPs to block its browser rival Netscape from getting access to customers. The analogy isn’t a coincidence, as the Microsoft case is controlling precedent. "
And google is going to say correctly that consumers are free to switch search engines. They are free to enter “bing.com” in google chrome and it will take them right where they want to go: to another search engine!
I note above that I am not sure google’s payments are pro-competitive. They probably aren’t. It’s fair to be uncomfortable with them. But to make an antitrust case on monopolization of search you are going to need more evidence than those payments.
And people were free to download Netscape.
But the thing is that people don't type "bing.com" nor "google.com" because they just use the browser search bar and don't bother with what search engine is being used.