Okay, it's not just about zippers, but about how much does the reader need to know about things the character does or wears.
The bathroom is another example. We don't often read about the characters going to the bathroom because it's not something the reader needs to know, it is just assumed. Zippers can be like that. The reader probably doesn't need to know every time the character zips up something. But there are times when they do.
Clothing can give a viewpoint into the world the characters live in. Sure every ruffle, button or zipper doesn't need to be described, but pick the right moment and you can not only show about the world but the character themselves.
One example is in Wheel of Time in the second book (The Great Hunt). One of the characters, Rand, is given new clothes and while he was raised as a farm boy, all of a sudden he finds himself stuck with clothes for someone of higher ranking. When someone is out of their element, it can show something about them with how they deal with the clothes they are put into or the clothes that others wear too.
While with epic fantasy we don't often think of zippers, but there are other places where they are used. Pulling zippers can also be an elusive moment for sensual scenes. There are quite a few things that come in to play when using clothing elements.
Do you mention clothing details in writing?
Does your character have to deal with a zipper?