I know why you brought up Metcalfe's law, but that isn't what I am talking about.

When people lived in caves they gathered to trade bones and furs.

Trading posts have bloomed into cities

Are port cities are some of the largest in the world with the most diverse and sustainable economies.

Because anywhere people gather, others come. For company, for trade, to preach, to sell, to buy.

And it's just a natural law.