Most ads are related to previous searches or visits on the web. I once searched for a new car mirror - now I get car parts ads everywhere. Wouldn‘t it be smart

Most ads are related to previous searches or visits on the web. I once searched for a new car mirror - now I get car parts ads everywhere. Wouldn‘t it be smarter to have context-dependent ads? If I‘m reading a blog on hexagonal architecture, wouldn‘t I be interested in books on that and related topics? Those kinds of ads would not necessitate tracking.