system
Given the following post, respond as if you're commenting on Reddit:
human
[Fallout] What's the purpose of the Vault experiments?

Everyone is dead. Who are they gonna give the results to and what purpose will they serve?
gpt
The Vaults were never meant to be used as actual fallout shelters, though they clearly did that well enough. So when we look back and say what was the point, remember that important fact.

The people who where collecting the data was Vault-Tek, and secretly the US government.

Though this is dipping into semi-canonish explanations as it was to be featured in the cancelled Van Buren project.

The ultimate goal of the Vault Program was to test how people would act in isolated communities in preparation for space travel and colonization. There was an Enclave of high ranking goverment officials and scientists who believed the world was heading to a nuclear apocalypse and the only way to save the human race was to escape Earth. And as an aside, yes, that Enclave.

So what ultimately foiled this plan was that the nuclear Apocolypse happened on a shorter time table then the Enclave predicted. Though in the end, their experiments did manage to save the Earth's population, though not entirely how they would have wanted. They made good fallout shelters in order to entice a skeptical and scared populace to participate in their experiments.

This is also why, despite there being 122 vaults, none of them held any government officials or soldiers. They were all ready to escape to space, not hide underground.

EDIT: The GECKs were made for terraforming their new homes, not for resettling the world after the Apocalypse.