I think I may have heard of that stuff. Something like 70 years ago people used to buy food items in bulk, so you needed to package your block of butter somehow. Wax paper was used back in those days. Since food manufacturers started packaging the products, the demand for wax paper dropped to near zero, so that’s why you don’t really encounter it much any more.
I’m sure some stores still sell it, but baking paper is so easily available that people just use that instead. Nowadays people would just use baking paper for the examples you just gave.
Edit: just went to the local supermarket and I found 15 stacks of normal baking paper on the shelf (at least 8 different brands) and one stack of wax paper. Apparently it hasn’t disappeared completely. Someone must be still using it for something.