In the new planet, the status of apes and humans is reversed. I dare to guess that the director uses this exaggerated contrast to imply that the natural functions of human beings have degenerated to the point where they cannot adapt to survive in the natural environment. In the end, the earth is also counterattacked by apes, which is a more exaggerated warning: even in the old nest and comfort zone of human beings, there is no possibility of extinction.
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