There is a financial incentive to make the search results worse. (More searches, more ads, more money.)

There is no incentive for adding false positives to lists of malicious websites.

Sure, until their "smart filters" start considering GCP-hosted websites as pre-verified and small self-hosted websites as malicious. You know, like they have been doing with email?

Chrome is big enough that a website owner can't afford a false positive on their malware list, just like they can't afford to have all their email end up in spam for all Gmail users.

Due to their near-monopoly Google also has no incentive to avoid adding false positives to their blocklist - provided they don't accidentally block high-profile targets. And if a CxO is screaming over your shoulder that your website has been blocked, arguments about "false positives" aren't very compelling: they'll just demand you move off the "shitty basement provider" and switch to "proper hosting, like the Google Cloud"...