If you see your wallpaper then you aren’t really doing anything.

I use sway these days. It's tiling, so I rarely see my desktop background anymore.

But not everyone uses a tiling system.

While I like the idea of avoiding having onscreen pixels wasted showing useless information, and I think that tiling systems do help achieve this, I avoided tiling systems for some years, as a fair bit of software still didn't play well with it (e.g. I remember default behavior with GIMP being half of the screen being the main window, half being the GIMP toolbar window). I think that we're past that phase now, but there are people who prefer stacking window systems for various reasons and don't use tiling systems.