I personally think (if a user's personal opinion counts for anything...) that all of the Settings we have under "Configure Desktop and Wallpaper..." (see https://itsfoss.com/content/images/wordpress/2021/01/2-kde-neon-wallpaper.png - also includes the options on the other sections on the left pane)
should be available in a KCM under system settings.

Not that it worths anything but here's my two cents

if you're not aware of it already

I like @ngraham idea as well!

That would be great!
It looks very bad the way it is ;)

@ngraham What's the state of this?

We don't build UIs where functionality is available only through a right-click. It's right there in our HIG: https://hig.kde.org/components/navigation/contextmenu.html. In particular, it wouldn't be acceptable to only let people change the wallpaper via a context menu.

My 2 cents:
That's also the first thing I do as soon as I get a new install!

Related to https://bugs.kde.org/show_bug.cgi?id=343690 ?
Oxygen had something like this. Breeze does not (yet)...