Before wallpaper referred to a computer screen at rest, it described the patterned paper that people pasted onto the walls of their rooms. It was ubiquitous in my childhood, and covered the walls of every room in the house. When I was old enough to choose the wallpaper I wanted for my bedroom, I was allowed to have one wall in a very exotic multi-coloured pattern that was quite pricey, provided I had a fairly plain, low-cost paper on the other three walls.
Wallpaper was replaced periodically because of wear and tear, with scuff marks and spills gradually degrading its appearance. The main cause of its replacement, however, were the coal fires that burned in every grate before central heating caught on. The smoke from those open fires spread into the home at times and gradually built up a layer of grime that disfigured the paper and dulled its appearance.
Replacing the paper was a major operation. The paper on the walls had to be soaked before it could be scraped off with a flat bladed tool, and the replacement paper soaked in paste on a trestle table before it could be carefully put in place on the now bare wall. It then had to be wet on its outside, as posters are when they are pasted up, so it would dry without wrinkles or bubbles. The upheaval sometimes went on for days.
Wallpaper is still used, of course, but I rarely see it because many people tend to use emulsion paint on their walls these days. I read that wallpaper "is making a comeback," but I have not noticed that in the circles I move in.