Waste

"What should we do with this?" the people asked, holding aloft unwanted items.
"Just throw it in the bin," said the leader.
That's just what everyone did, blindly, with everything they didn't have a use for. It went on for years.
Eventually all the bins were full and there was nowhere to empty them. Every ocean and river was full of rubbish. Every city had rubbish jammed underneath it. There was no room left.
"What should we do with this?" the people asked, holding aloft unwanted items.
"Burn it," said the leader.
And so everything was burned. Thick black smoke polluted the atmosphere and the people became ill.
The people all eventually died.
Thousands of years later the planet was discovered by an advanced species.
"What should we do with it?" one of them asked.
Their leader looked at the ruined planet.
"Destroy it," he said.