The suspension of a vehicle has 3 components. First is the tyre, second is the spring and third is the shock Absorber.
The main function of the shock absorber is to regulate the movement of the spring and ensure the saferide of the passengers. Even with new tyres and new brakes, unless all shock absorbers are in good working order vehicle safety is compromised because of reduced wheel contact with the road.
But what if it does'nt have shock absorbers but it as spring? Your car can still absorp bumps but but the undampened suspension means that the vehicle continues to bounce and causes the tyres to leave the road.
With Spring and shock absorbers, not only the car absorbs the bumps but also the shock absorbers dampen the spring and prevent from bouncing