I wonder if there is some hidden value to fashion trends. There are obvious reasons to wear clothes like you mentioned, to stay warm, protect from elements, carry your wallet, etc. but it also helps you identify in group/out group. Your style conveys your age and generation. Your music preferences. Where you are from.
I think web design can convey similar things, sometimes at the cost of utility. For example, a website may want to convey that it’s for professionals and businesses. Or that it’s fun & silly like a toy. Or that it’s for academics and learning. The style of the site helps to identify if you’re in the right place for your “group”. users can look past bad UI. In fact, they will often complain if you decide to “improve” the UI without their consent.
A lot of fashion trends can also come from advancements in materials or changes in their cost which allow new kinds of experimentation. As an example (not necessarily positive) fast fashion was enabled by ruthlessly cutting costs of production. Polyester was really big in the ‘60s after its commercial release. And so on.
I think web design can convey similar things, sometimes at the cost of utility. For example, a website may want to convey that it’s for professionals and businesses. Or that it’s fun & silly like a toy. Or that it’s for academics and learning. The style of the site helps to identify if you’re in the right place for your “group”. users can look past bad UI. In fact, they will often complain if you decide to “improve” the UI without their consent.