One thing I do know for an absolute fact is that my aluminum horse trailers hold up much better then the steel trailer that they replaced. Every time a horse kicked the side of the steel trailer it dented and the paint peeled. I was constantly sanding and painting it to control rust but that was a losing battle. Five years on the first aluminum trailer and no rust or dents, except for the steel wheels that need to be sandblasted and painted. I still have an aluminum canoe over 40 years old with a few dents but it still works fine and has not required any maintenance.
I love the aluminum body on my 2016 F150, no rust or dents in it. On my old F250 the bed had cosmetic dents from tire failure and I tried to find one in a junk yard to replace it but they were all rusted out. I will stay with aluminum if given the choice. I am about to sell an old Nissan truck mainly because it is rusting out.