You misunderstood ... of course, not everyone can make attractive art as content for a wallpaper.
And not everyone who makes art also respects some useful limits for wallpapers, e.g. that they should be decent and not hide icons on it due to high contrast.
But everyone could convert art into a format which is suitable as wallpaper for specific devices. All one needs is to know how.
And if it is just resizing an image to a specific dimension and saving it in a specific format.
Like I made my own ringtones for my Nokia 6300i: I used a sample editor to cut a loopable part out of a song, and used the NeroAACEnc encoder to convert it to AAC. Then I uploaded it to my cellphone via USB cable. So simple. And now I have a ringtone probably noone else has.
Yet...
Anyone interested? ... And let's see if you can detect out of which songs they got extracted:
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