What does a hub actually do?

A hub lets you carry people who are neither starting nor ending their journey there. That is the whole point of one, and it is where the money in this game eventually is.

Atlanta to Dubai is only a few hundred passengers a day as a city pair. Emirates flies it with a widebody because the aeroplane is full of people going on to India — the Dubai market is not what fills it.

Route economics tells you whether each of your hubs is working as one, and if it is not, whether the problem is seats, timing or geometry.