It was probably a decade ago and I recall using something within Google that would tell you about who they thought you were. It profiled me as a middle eastern middle aged man or something like that which was… way off.
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the ad game is not about profiling you specifically, it's about how many people in a group are likely to click and convert to a sale; they're targeting 6 million people, not you specifically, and that's balanced by how much the people who want the ads are willing to pay.
palantir or chinese social credit, etc., is targeting you specifically, and they don't care about costs if it means they can control the system, forever.
That platter of details is not shown to you, the consumer.
What you are experiencing is that your ad profile isn't valuable to most bidders, ie you don't buy stuff as much as other people do, or your ad profile is somehow super attractive to stupid companies that suck at running ads who are overpaying for bad matches.
It is not evidence that google knows nothing about you.
Google is pleased that you think they don't know you. It helps keep the pressure down when people mistake this system for "Perfectly target ads". The system is designed to make google money regardless of how good or bad their profile of you is.