First off, sunlight makes heat or is heat depending on how you look at photonic energy. And that’s generally bad. To make matters worse, sunlight happens to be an active ingredient for photosynthesis. Many types of fungi just leap for joy when they see it. And worse yet, it seems to have mechanically disruptive effects, particularly in fluids like essential oils, and cooking oils which is why we store such things in dark colored bottles. It is, after all, photonic energy. Sunlight heats and cools things unevenly, driving moisture from one place to another. Sunlight attracts certain creepy crawlies. It used in drying of course, but this is a method of preparing food for long term storage. The storage almost never has anything to do with sunlight longterm.