Oh boy. They don't host these ads, there are plenty of ad providers that happily do though, outside of Google businesses (Meta). Google also isn't one homogenous business, Android people don't have direct access to the ads people.
This is about scams because 99% of all apk installs come not from basement power users installing cracked apps, but from the older people that are all too trusting to the internet that they're browsing.
I can also tell you from experience that malware Google search ads are common. Anyone who used to use Optifine knows that without an adblocker it was common for fake Optifine sites to be at the top of the results with a tiny marker saying "sponsored" or "ad".
This is about scams because 99% of all apk installs come not from basement power users installing cracked apps, but from the older people that are all too trusting to the internet that they're browsing.