I am confused about chassis flex in general. Why would you not want the car to be perfectly stiff (consistent and predictable), and then rely on the shocks/springs/damping to adjust traction?

It seems counter-intuitive to me to have what could be and unpredictable 'spring' or possible inconsistency of flex, in the middle of the car to add traction - then twiddle with the other suspension bits to also adjust traction????

Thoughts on this? (vehicle engineering types - please pontificate! )