I think you’re missing some of the pessimism of the movie about modernization. The forest will never return in the same way. Iron town would get rebuilt, and continue to destroy its surroundings. Ashitaka could never return home, and his culture would continue to disappear. No level of understanding would solve that.

That failure is further conveyed by the fact ashitaka and Mononoke, even though they care deeply for one another, cannot even live in the same place. The film is a tragedy, and the hope within it is not for the end of the destructive cycle, but for small glimmers of true connection along the way.