Sarcasm aside, how do we propose they determine what is truth? If we assume the internet is full of information and more truthful than not, then Google’s assumption could be accurate. Of course they do try and solve this with the knowledge graph and expert curation. Connections to verified information might give validity to that information, but not always.
Google has been transitioning to attempting to provide a "truth engine" for several years. Whenever I try a complex key-word search, it suggests a question format for it (often with worse result but sometimes OK). When I have finally got the key words down to filter just what I want, google whines about "Not very many results, here's what you should do..." and, of course, Google often gives explicit answers for questions in it's search results (a notable percentage of which are wrong as noted).
And Google being half-assed truth engine is all sorts of bad...
The problem is in the presentation: Google's tools in general, not limited to search, present themselves as though they can identify truth. That's the flaw, the lie, if you prefer.