Tracking your butter use is actually kind of crazy when you say it out loud. They're building a profile on how much fat you put in your cookies. That's a level of detail nobody needs to know.
My grandma's cookie recipe from 1972 is on a stained index card. It never asked for my location or what I bought last week. Those cooking apps probably know how much butter I use in a month. Why would I want them watching my every move?
Yeah, the butter thing is weird, but honestly that's probably not the main data they want. When you mention location and what you bought, that's the real target. They'd rather know you searched a cookie recipe, then drove to a specific store, and bought their brand of chocolate chips. That link between your phone and your real world shopping is way more valuable than your actual recipe.