Towards the end of the game, people will not want to trade with you because doing so will bring you closer to victory, so you’ll have to rely upon autarky to grind out those last few victory points.
For a game that’s about trading with other players, it’s easy to forget just how crucial ports are, especially in the end-game. Towards the end of the game, people will not want to trade with you because doing so will bring you closer to victory, so you’ll have to rely upon autarky to grind out those last few victory points. Ports help you in that regard by giving you favorable trading terms at the stage of the game where you’re already producing a lot of goods anyway. So make use of them, get the resources you need for cheap, and laugh as you achieve that final 10th victory point.