That's an interesting observation. In Italy milk and eggs are not typically kept in the refrigerator in stores, or at home. They are kept on regular grocery store shelves in the store, or in the cabinet at home. People with small apartments, meaning many people, store their milk and eggs in their empty oven to make maximal use of available space. Milk and eggs aren't considered to be foods that need refrigeration.

I know why that is for eggs. In the USA, salmonella in chickens is almost universal. Eggs have to be refrigerated to keep the bacteria count down. They must be cooked before being served. It is why menus in a restaurant say, "Raw eggs can cause disease." It is why eggs, "sunny side up," are discouraged or no longer served, especially to pregnant women, because the yolk on top may not get completely cooked. That is why they recommend having them at least, "over easy," because turning them upside down makes sure that the yolk that was on top hits the frying pan and gets cooked.

In Italy, instead of worrying about refrigeration and cooking, chickens are given a salmonella vaccine before they lay eggs so that they don't need to be fed antibiotics with their meals, and their eggs don't need refrigeration. It's just a different approach.

I don't know why milk is also just kept on regular, non-refrigerated shelves in the grocery stores, and not in a refrigerator, or why people at home just put it on the shelf, or in the oven. I suspect there is some similar reason, having to do with germs. I suspect these different approaches have the potential to have a large impact on flavor.