Wallpaper Engine costs $3.99/£2.99/€3.99, but for that you get over 700,000 wallpapers, and the peace of mind that your desktop needn't look lacklustre ever again.

Click Desktop & Screen Saver in the preferences pane. Select one of the official wallpapers that come with macOS, such as "Catalina," "Big Sur," or "Monterey Graphic," and set it to Dynamic.