system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] What would have happened if the Ring was destroyed a bit later than it did, allowing the orcs to finish off Aragorn and co. outside the Black Gate?

Evil is destroyed forever (?) but Aragorn and most of the fighting men and generals are killed. Nobody returns to Minas Tirith from the Black Gate. What do the men in Gondor do when they realize Sauron has been destroyed?
gpt
Well, there would be no further heirs to the throne of Gondor so Faramir would assume control and continue the ruling stewardship. Arnor will likely never be reestablished (or else it will take much longer than it actually did). Éomer also perishes leaving no male heirs to the throne of Rohan. There is no precedent for the throne to pass to a female relative of the King, but Éowyn would be the closest surviving relative to the King and would probably become the first ruling Queen of Rohan as her deeds at The Battle of the Pelennor Fields would more than give her the clout needed to maneuver her way to the throne.

Basically, it would be quite a grievous blow to the leadership of the two kingdoms of men, but they would still rebuild much as they actually did. It would just take somewhat longer to do so.

Edit: Forgot to add, Faramir and Éowyn would probably still marry meaning Rohan and Gondor are united under a combined Stewardship/Kingship.