I won’t say nobody was, but very few people in the military were ever carrying 100-125 pounds in a backpack.

A lot of the weight was distributed elsewhere in our body armor/plates, weapons, helmet, NVG, ammo/batteries radios on the front of our vests, etc

Even then, the motto was “light as right”—we try to strip as much weight as possible by doing things like taking everything out of its container, carrying loose amino instead of extra magazines etc

And to your point, yes, my knees and back are still permanently fucked up from it, and I never even jumped much.