We were not the first and if we vanish we wouldn't have been the last life on Earth that would be destructive.

https://en.wikipedia.org/wiki/Oxygen_Catastrophe

Such apparently is life on Earth. We are not special.

But again, it is only us humans that value diversity. You would be obliterating the only species that would appreciate the thing you are obliterating them to preserve.

Not substantiated in geologic history. Life collapsed repeatedly.

You're right, but did it collapse because of the behaviour of a single species?