Here's a remake of backgrounds from this thread that I made since the links were dead. These were inspired by u/rzalexander and made with free illustrations from illustrations.co. I've tried to adapt the illustrations to iOS 16's new home app, so that the text and icons are visible.
I've also made companion backgrounds for use with iPad and Mac. Since those windows resize all the time, using two tone and illustrations was a no-go. So they are just one colour backgrounds (I have one using the dark colour and one using the light one. I've used the latter).
I've made backgrounds for 13 different rooms (3 versions for each room).
Hopefully this can be useful for someone! At least I've enjoyed using them myself.