There are people who assume that all dresses are at least somewhat formal, regardless of the material that is used to make them. However, there are lots of casual types of dresses that are in style and have been for some time at this point.
People often want to wear casual dresses so they will have some more control over their wardrobe and more options. It’s sometimes easier for people to feel comfortable outside for a while when they have these sorts of dresses, which is one of the reasons why lots of people associate casual types of dresses with the beach and summer days.
It’s also somewhat easy to make a more casual type of dress seem formal, and the other way around. Some people will pair their formal dresses with a jean jacket or something similar, and they will end up with a dress that seems much more casual than it would have been without that accessory.
The right set of accessories can make lots of clothes seem much more and less formal, which will give people more choices when it comes to wearing them or using them. When people are able to add to these outfits, they’ll have an easier time making the most of each garment that they have.