They don't have to eat each other. https://en.wikipedia.org/wiki/Great_Oxygenation_Event https://en.wikipedia.org/wiki/Great_Oxygenation_Event The vast majori

They don't have to eat each other. https://en.wikipedia.org/wiki/Great_Oxygenation_Event https://en.wikipedia.org/wiki/Great_Oxygenation_Event The vast majority of life on Earth has been wiped out simply because other life created inhospitable conditions for them. Even if multiple events created life, if the wrong life is created, it will die.