One time a long time ago (1973) I had a 3/4 ton Dodge power wagon full of gravel. I backed up and put on brakes in 4wd. The front brakes stopped the front wheels and the rear wheel brakes did not stop the rear wheels. The front end U joints both broke. It made a very loud noise when they both broke.
I learned a lot that night. Two wheel drive and easy on the brakes when hauling a heavy load. Yes I do agree the front end U joint or cv joint which ever you have is the weak point of drive train.