those planes perform and can take a beating without issues at all,
No airplane is invincible or immortal. Just like our bodies, hard use will result in problems later on. As a mechanic I have found cracks at the bottom of the aft doorposts. Rough ground does that. Landing gear mountings will suffer. The 170's tailwheel mounting area on the tailcone cracks. Cessna taildraggers suffer loosened elevator balance horns and broken balance weights. The wing struts have been known to crack through the attach lug rivet holes. I found one like that on a 180 floatplane. The nosegear mountings on all but the 150 were never designed for rough strips, and the mounting bracketry can work loose. A hard landing can buckle the firewall and internal tunnel structure. Various bulkheads in the tailcone crack, often from rough handling. The horizontal stab and elevator bottom skins and leading edges get beat up by rocks thrown up by the prop and wheels. The prop itself gets chewed up by rocks, and if those nicks aren't addressed, the prop blade can crack. If you lose a big enough chunk of blade, the vibration could tear the engine off the airplane, and now it won't even glide. CG is way aft.
None of this is cheap to fix. It's fine if you own the airplane, but when it comes to resale time you could find that the airplane has lost much of its value when the prebuy finds so many cracked and loosened components.
When I was young I was lifting far too much weight at work, often well over 200 pounds at a time. The older guys told me I would wreck my back. I told them that I didn't feel anything. I was strong. And stupid. Now I have constant pain from the arthritis caused by the wear on those joints in my back and hips. The old guys were right.
Cessna engineers didn't design their airplanes for extreme operations. They were aimed at normal operations, on paved or at least improved dirt/grass/gravel. Sure, there are mods to beef up this or that, but strengthening one area can transfer the damaging loads to weaker adjacent areas, and stuff suffers anyway.
I like the idea of extreme bush ops. But I sure wouldn't use a Cessna for most of them. If I did, it would be a 185, and even then one has to expect some wear and tear, and landing on sizeable rocks on a gravel bar is going to do some damage. I would be inspecting the gear legs and axles regularly. Those axles are only aluminum, and they are at the roughest end of all that. A busted axle would be a bad deal.