Why is the Solar System Flat?

The video explains how the solar system formed from a nebulous cloud of gas and dust, coalescing into a flat disk due to gravity. It explores why many cosmic structures, like galaxies and black hole accretion disks, are flat, attributing this to collisions and the three-dimensional nature of space. The video contrasts this with four-dimensional space, where flatness doesn't occur due to the presence of two planes of rotation. This flatness is crucial for the formation of stars and planets.

What distinguishes the behavior of particles in four spatial dimensions compared to three dimensions?

Why is the flatness of the solar system considered beneficial for the formation of stars and planets?