What is the Importance of expressing coulomb's law in vector from ?

Explanation

As in vector from `hat(r)_(12) = - hat(-r)_(21) :. vec(F_(12)) = vec(-F_(21))`
It shows two charges exert equal and opposite forces on each other. So Newton's third law is obeyed.
As Colulomabain force acts along `vec(F)_(12) and vec(F)_(21)`
i.e., along the line joining the centres of two charges, so they are central of two charges , so they are central forces.