Even replacing "need" with "want", there's plenty of room for entirely ethical adtech that just isn't done because it's slightly less profitable than the unregulated craziness we have.

For a simple personal example, I have weirdly-shaped kitchen cabinets, and it took me months of trial and error to find a cutlery organizer of exactly the right size to fit. If I'd had some way of plugging in drawer measurements and getting back a list of things that fit, that would have been a purchase the first day.

You're not describing advertising, but rather search. Advertising applied to your situation would either mean that the size of your drawers were stored in some surveillance database to foresee your need for odd sizes, or more likely being repeatedly bombarded with ads for ones you can't use.