I don't think a shopping comparison channel, which actually doesn't command a particularly large share of price comparison sites, is comparable to life savings. Surely, you'd take these results with a pinch of salt and 'shop around'?
And at least the EU commission seems to have come to the conclusion that Google has used its power that it got due to its successful search engine to promote their price comparison site more than it did competing sites, and that not solely based on merits of the site itself.
Whether people could potentially evade the manipulation if they cared enough is irrelevant, just as it is irrelevant whether a fraud victim could have figured out they were being defrauded if they had cared enough.