Why are default wallpapers and icons in all Linux Distros just so bad?

Been using Linux for about 20 years now. More than a decade as primary. Always have a few VMs for testing various things, obviously servers on Linux. But this obviously regarding desktops.

KDE, Gnome, XFCE anything on any distro (Fedora, Debian, Mint, Ubuntu whatever). The default set of wallpapers of most Linux distributions is just ... meh! I get it - macOS and Windows wallpapers are shot professionally and cost a lot. So that can't be done. But there are enough professional photographers on services like Unsplash. I'm sure asking some of them to be featured for the "default set" won't result in a null. Someone would agree for it. I remember that one guy was proudly showing off his creation for being accepted in OpenSuSE somewhere around 2012-13.

I am not saying I can't set custom wallpapers. In fact we have options to use Unsplash and Nasa as a source! It's just that the defaults don't look that good. That's the whole point I had.

I think the same thing applies to Gnome and XFCE icon set (KDE is a little better, but only a little) - they too look quite bland while community has created amazing icon themes (one of which can be improved and included with creator's permission)! I like Ubuntu's default icon set a bit though (and I have grown to dislike the rest in that distro).

Why don't we do it then? What's stopping us? I am sure there is a genuine reason which I am not aware of.

PS: I didn't know that this simple question will irk the community enough that I would get downvotes. Well, whatever.

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