Just make it illegal to target ads based on the people viewing them. You can still target to things like contexts, venues, areas, etc. but it would rule this out and it would eliminate the justification to farm so much personal info.
I too am in favor of bankrupting Google and returning to the old model of advertising where you put the car ads on car magazines and computer ads on computer magazines.
Aka all of them? I agree this is despicable, but I’m curious how you make this illegal and not all of advertising.