With the OS's built-in wallpaper rotation, every time the wallpaper changes, there's a crossfade effect. I've recreated the wallpaper rotation myself to have more control over how the next wallpaper is selected, along with customized timing and other features. However, I’d like to recreate the crossfade effect.
While I’m by no means a fan of animations, I find it slightly jarring when the wallpaper changes abruptly without any transition.