Google AI Overview cannot be trusted at all. They will take a sample size of 1 (!!!) and present it in the AI overview.
How I found out: I made a comment on reddit on a very niche topic for which no google hit or and thus no AI overview existed. To my surprise the next day when searching for my own reddit post, google would happily copy my reddit reply almost verbatim into the AI "overview" box, linking no other post but mine. And my reply was also the only google hit.
It also just wraps it in context which is entirely missing in the underlying post but matches the way you asked the question. To the extent that it's just wrong.
Your search may be like: "What is the most common dimension for obscure item X?"
And you are the one person who stated the dimensions for your version of such an item, but didn't in any way imply its typical or that there even is a typical dimension. And like you said, it's just you, not 20 people saying the same thing.
And google will happily say: "Typically item X comes in [the dimensions you state] because [some reason it totally made up]."
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