Every developed country has major ports accompanied of cities that become an international reference to the world, such as Shanghai, Hamburg, Liverpool, etc. This is not the case of Mexico a country with great potential given that is between the Atlantic and Pacific Ocean; between the the old powerhouse (Europe), and the emerging one (Asia).
And to understand the relationship between the existence of ports and the emergence of big cities we begin to answer a few questions:
Why ports are important?
They facilitate trade and trade is the source of economic growth. When people specialize in different task and work together they can generate a greater output that the same number of people working on a whole process independently. A similar phenomenon applies to countries, when a country prosper in certain industry it can supply high valued products to other countries all over the world and this is where ports become critical.
Why cities grow where ports are?
Economic activity brings more economic activity. A virtuous cycle begins when products from all around the world concentrate in a single place, secondary economic activities start emerge. Activities to sustain the main industry start to emerge such as shipyards, communication facilities and so forth.
The consumption industry also starts to emerge, restaurants, cinemas satisfy the entertainment needs of the current inhabitants or visitants. These activities could become more sophisticated, specially if there is bonanza.
An additional factor of economic growth of port cities comes from the knowledge spillovers that occur from the interaction of people of all around the world bringing novel merchandise and services to the port cities.
So, why Mexico does not have big urban developments in its port-cities?
I have to keep researching. Maybe the ports have not grown enough and the virtuous cycle stall, another reason could be that the economic activity of the port is isolated, to some degree, from the other economic activities from the city.
An evident example is Manzanillo, this port moved 2.4 million TEU of goods in 2020, making it the first one in the country, but the population of its city is less than 200k habitants and the contribution to the national GDP is among the lowest of the country (taking into account its state: Colima).
In order to exploit the potential of this port cities there has to be an answer to the last raised question.