You've missed a lot of the point here. MapQuest isn't something Google cares about, but it is an extremely popular search term, particularly among the computer illiterate, who learned what it was back in the 90s, and have ever since considered it "where to get directions". Like many other search terms, it's a high value term for malicious content, and Google's happy to rake in the cash. While "Google does not sell your data", they're more than willing to redirect you to a malicious browser extension that does.

Those of us in the tech industry don't use MapQuest. We don't click on ads. A lot of us have ad blockers. So we don't really think about the fact that the cushy online presence adtech has built for us is built on taking advantage of less technologically savvy. You may not pay for Google, but indirectly, the old lady down the block does, every time she has to take her computer into Best Buy to have the garbage scrubbed off of it.

And where the antitrust drops back in: Google doesn't let people bid on ads for their own products, so "google maps" never returns a malicious map site.

And, as I noted above, this site's been heavily promoted in Google Ads for years, at least five, and there's no way to report it in Google Search. Several Google employees are likely reading this thread who have the ability to do something about it or know who to escalate it to, but I'm reasonably confident it'll still be there next week.