That's quite a serious accusation :). One that is not substantiated by the facts:
https://blog.google/topics/ads/how-we-fought-bad-ads-sites-a...
It's like somebody saying "Tesla cars suck - they explode". And Elon Musk comes out and says, "No they don't, here's the testing/validation we did". And you say "Oh but...but....you work for Tesla. It must be lies!"
If there's factual inaccuracies - of course, that's a different story. But you seem to be simply saying, "They must be lying, because that suits my narrative, so I'm not going to bother trying to refute it".
https://gimletmedia.com/episode/78-very-quickly-to-the-drill...
But malicious content (even on the SERP) is common enough that one of the most effective steps that you can do to protect senior citizens from malware is to install a good ad blocker. The ironic thing is that the search algorithm does a decent job of filtering out malicious sites from appearing on the first page, but that does no good if there is a malicious ad right above the filtered results.
Even if Google is removing "x million bad ads", they are merely replacing bad ads with other bad ads. Removing bad ads doesn't significantly impact their revenue. I'd argue that while Google is willing to make gestures like removing some ads, they are unwilling to do what's necessary to protect users: Stop serving ads entirely where malicious ads are particularly prevalent, and clearly highlight the difference between ads and search results.
EDIT: Here's some captures I did this morning of Google results on incognito: https://oasis.sandstorm.io/shared/nTZcQOHrTgnM-90dAfmut0AX_c...
Almost every senior citizen I've ever had clean up malware for got it from a malicious search ad. And the tech support scams they continue to list take advantage of tons of people as well.
I've pointed out before that Google happily lists phone numbers of tech support scams on search terms for Windows tech support, but doesn't show ads at all if you look for Chromebook support, pointing you straight to their official contact.
As a note, if anyone would like to see examples of this in action, I can go get screenshots and example links and everything, it just takes a little while to put together, as I would prefer to offer evidence of what I see "today" rather than any past examples I might have.