I agree with your last bit, and I know plenty of people who are clearly manipulated by their news feeds and targeted advertising, but I’m not one of them. I don’t use ad blockers because it’s a valid revenue mechanism - I have friends who pay their bills through advertising. But I’m blind to them, I’ve never clicked on an advert and actively avoid suggestions.
I’m worried about the societal consequence, but doesn’t that issue need to be addressed by engaging in the politics, not by me using Google less? Data harvesting is unavoidable without huge inconvenience, and life is hard enough.
I feel the same way about climate change - I can reduce, reuse and recycle all I want, but I see my neighbours driving and flying everywhere and filling their bins every week, I probably sacrifice to make zero difference.