EDIT ---
Ok, I get it now. Personalized ads = surveillance. Fair enough.
Doesn't the whole GDPR already cover it though? You can opt out of the surveillance.
The categories are much to broad to be useful. I've been vegan for about 7 years. The internet thinks I like "food" and shows me ads for meat products all the time. Good to know I'm wasting the ad dollars of companies I think are bad, but I think it's gross and I don't want to see it.
And yet, I still think they can be harmful. Think of someone with alcohol use disorder who recently stopped drinking, or someone with BED who's decided not to keep junk food in the house. You don't think constantly seeing ads for alcohol/junk food would make such a person feel bad or even impede their progress? Why would that be the cost of them opening any website at all?