One of my toy theories-of-everything is that we live in a branch of something akin to a Mandelbrot set. A trivial rule is all that is needed to produce infinite complexity. Sure, zoomed out a fractal can look simple, and even zoomed in (a lot!) it still looks trivially repeating, but if you zoom in enough eventually the complexity becomes high enough to represent something like the universe and the life within it. You can even squint at it and just like how the Mandelbrot set appears to fork repeatedly, parallel universes (like in MWI) could be forking off by the dint of following one path or another through this fractal space.