Actually, the useful part of the geostationary orbit is 1 dimensional, because the satellites have to be at the right height and over the equator. It's called the "Clarke Belt": https://en.wikipedia.org/wiki/Geostationary_orbit
But anyway space is very big and the probability of collisions is still low. Two geostationary satellites out of control would probably not collide, they will pass a few hundred of meters away in any direction. The big distance between them is mostly to avoid interference between the radio signals.
But anyway space is very big and the probability of collisions is still low. Two geostationary satellites out of control would probably not collide, they will pass a few hundred of meters away in any direction. The big distance between them is mostly to avoid interference between the radio signals.