Aluminum rots when exposed to something that causes electrolysis. Not an issue in a climate where there is no freezing temps or snow or where the roads aren't treated with brine, CACL or rock salt, all cause electrolysis when moisture is present.
The company I retired from ran a fleet of aluminum trailers and we were constantly repairing them. Biggest issue with aluminum is where the steel (axle pads, suspension mounts and steel kingpin plates contacted the aluminum. That is where corrosion really accelerated. I'm not talking sheet material either. I'm referring to thick aluminum extrusions.
The other issue is, aluminum is secured to aluminum with steel fasteners. Steel and aluminum is always electrolysis prone no matter how the area is pre- treated.
IMO, the best way to treat rot is to mitigate it as much as possible with preventative maintenance. A regular (every 3 month) regimen of checking seals and caulk and repairing any intrusion points seems to me to be the easiest answer and by far the least expensive both in time and dollars spent.
RV's will almost never be built like marine products because the cost to purchase would be beyond the reach of the prime market the builder want to sell to.