Humans can pollute a lot more land/water than they occupy with their physical bodies.
I bet that Ganges River is not as clean now as let's say 10 000 years ago.
One big oil tanker crashing and leaking can cause a lot of damage even in less populated areas (e.g. Alaska 1989).
On local scales I agree, humans are retarded and should be more careful. Mostly because you don't want to live in a house filled with trash either.
But the doomsday narrative is unproven, potentially inaccurate and for now mostly political garbage.
Politicians will tell you what you want to hear, and a narrative that destroys our planet is of great interest to everyone. Large swabs of science and politics are just as much under a blanket as big corporations and governments are, so don't just buy everything. Especially media headlines.
I'm not trying to be a cunt here, but it's important not to talk about things you don't even remotely understand the scope of as if they were fact. That doesn't help anyone and actively hinders us from identifying the real story.