"Humans are necessary for the planet to function properly because they are responsible for keeping the planet clean and habitable. They also help to preserve other species and maintain the planet’s ecosystem. Without humans, the planet would slowly become uninhabitable."

Please explain further. Humans have been here for only about 200K years, while life has been here for much longer. Humans have caused much pollution and many species extinctions. It seems to me that the demise of humans would make this planet much more inhabitable to other species. What am I missing?