Can't even buy chicken in peace

Why make money if you can make MORE money?

They probably aren't showing you ads. They are probably inserting trackers to tag you as a person, a purchaser, who likes chicken and is willing to pay for food, for delivery etc. the size of your order may hint at demographics, like family, kids. The address.gives useful data, the type of credit card. What kind of software and hardware loaded the site? Etc etc.