IDK who needs to hear this but stainless steel is a relative term. It still rusts eventually, especially if it gets wet, triply so if it gets salty and wet. If you're making, say, a truck out of bare stainless steel, you should probably put some paint on there.
We were not painting trucks this whole time for purely aesthetic purposes. Sorry, "skipping the paint" does not qualify as "disrupting the auto industry."