Original sin is the idea that a dude ate an apple some number of thousands of years ago and an all powerful (and allegedly all knowing) being got grumpy at him for it for some reason and now we all suffer for his intransigence.
In fact, the concept of original sin requires that we exist in a state of punishment for that sin permanently, not that we continue to benefit from it by, again, existing in the wealthiest civilization that has ever existed on this planet.
This is again a poor analogy, framing us as victims of an aggressor who wants something from us that we cannot give.
As for the geneva conventions, please note that colonial relations to indigenous people violated just about every single one of the geneva conventions. Forced resettlement, biological warfare, collective punishment, the destruction of non-military targets -- it is not "collective punishment" to expect there to be at least a moderate reparation for crimes committed. What is even the point of the concept of "war crimes" if you can get away with them just because "oh it's been too long".