If you're driving on rough roads, a soft suspension, within reason, is what you want. (Not soft as in worn out, I just mean a factory buick setup in good condition) I've owned a few vehicles I've modified the suspensions on. 2 motor swapped accords, one with ground control coilovers and revalved bilsteins, and the other one on Tein coilovers with matching struts, with adjustable valving. Both of those hondas were completely undriveable on gravel roads. The first one didn't even smooth out on pavement until above 80 mph. Race car stuff sucks on the street. I also had a 2011 vw golf, weirdly, that thing rode like the hondas, despite being 100% stock. Bumps in the road felt like kidney punches. The other vehicle I modified (to a moronic degree) is my 95 silverado. The gas motor came out in favor of a 96 12 valve. I swapped a dana 60 in the front of that, cutting out the independent front suspension. Despite the high unsprung weight of the solid axles, because of the tire diameter, that would roll right over any smaller bumps like ripples on gravel at any speed. (37" inch cooper stt pro mud tires.) But that unsprung weight would reveal itself hitting larger bumps, giving you a strong message to slow down.
I'm just saying from my experience, if you're driving on rough roads, you don't want stiffer springs and more damping. At least not more high speed damping. Low speed damping would be good for body control with soft springs. I suppose it's possible the struts would last longer because they wouldn't move as much, but they would shake and rattle the car apart, and put more force on other suspension components, wearing them out more quickly.
I guess one exception to this would be if you could dial in a little more rebound damping if you're driving on roads with potholes. More rebound damping would prevent the tire from falling down as far into the pothole as you drive over it, dramatically reducing the impact. But that same damping, if you're going around a curve with ripples or bumps, can cause the suspension to "pack", or compress, and the car will skip over the bumps, causing you to slide outward in the turn if you're pushing it hard enough. There's a Lot of engineering that goes into suspension design.
