OP, whatever happened to begin crushing your bed, is not normal, IMO.
Only put 25-30k miles on our 07 Dodge with the same camper and there was minor denting of the bed floor at the very rear like yours. But it happened first trip and never got worse. It actually served to center the camper up, lol.
Looking back, it was probably the heaviest the camper was ever loaded and was definitely the worst roads. We were moving to AK and camper our way up there, loaded for who knows what on the Alcan.
That said, you’ve figured out that your bed is done for. Also looks like the bottom of your camper may be collapsing as, if you’ve had the belly out of it, the weight is mostly all supported around the perimeter.
I’d bet a new (used) bed would hold up for quite a while. But I’d also bet you’re loaded heavy. (Full time and the amount of damage present)
Beefing up the mounts isn’t too difficult with the bed off and truck beds are readily available and not too expensive. But have to reinforce and get right color or paint, etc.
Flatbed is the easy, durable option if you really think it’s all the truck beds fault and not the manner of use. And a flatbed won’t add a bunch of weight unless you add a bunch of weight, IE heavy steel bed, with many options, tool boxes etc.
Good luck getting it fixed. And check the camper. It may be damaged underneath.
Couple other suggestions. If you get a truck bed, a sheet of plywood will spread the load better. Prevent localized buckling. Doesn’t solve the crushing of course.
Also the camper DOES move around. Like you said, the right bump or turn or braking etc.
I padded the front off of the bottom of the bed, so the camper wouldn’t connect with the top edge of bed. (It did, first trip and dented the bed front) and also used a board along the fender well, sitting on edge, to keep possible lateral movement to a minimum.
Bottom line, you found the service limit of a truck bed with a very heavy load in it. Could have been some specific initial factors that started the damage or not. But you know how to fix it, but have just procrastinated for a (long) while about fixing it.
