The people we found here were the scattered and broken dregs of the cultures that existed thousands of years ago. They were on a clear path to extinction that was already inevitable over 2000 years ago due to brutal wars that wiped out all traces of the civilizations they had built. When they did get access to higher level technology their first impulse was to use it to murder each other with greater efficiency. They were already well on their way to disappearing long before we got here.
The people we found here were the scattered and broken dregs of the cultures that existed thousands of years ago. They were on a clear path to extinction that was already inevitable over 2000 years ago due to brutal wars that wiped out all traces of the civilizations they had built. When they did get access to higher level technology their first impulse was to use it to murder each other with greater efficiency. They were already well on their way to disappearing long before we got here.