You could otherwise attempt a wallpaper slideshow, but you will need to fiddle to get widgets out, and you'll probably need to do custom scripting to keep a good enough setup
Old-style CRT screen savers would indeed be the solution here, but I have to bet they're another lost technology that somehow can't be implemented. Not to mention that if they attempted it today it would probably require 50 libraries and use 20% of your GPU capacity

