Well, that was because the greatest innovation of western civilization- the transnational corporation hadn't been invented yet!
Empires rise and fall, but Great Britain's ability to establish a global empire in the 18th century had less to do with their ships and the size of their navy, but with the rise of the East India Company...which was given a charter by the Government to do the dirty work of extracting wealth from nations being colonized. The East India Company became the first of what would be a multitude of international corporations that went about the world extracting wealth.
The only change after WWII in the modern era, is that the globalists have realized that they can hide the hand that controls international finance and corporate control of the resources of smaller, poorer nations merely by installing a bunch of co-opted lackies in charge of the political apparatus of state. These dictators, despots and presidents-for-life are the ones who have to deal with unrest and are richly rewarded with their own percentage cut of the profits for turning their nations and peoples over to the globalized order for extraction and exploitation.
The most surprising fact I recently learned about the earlier colonial era was that India was likely the wealthiest and most productive nation in the world until the British, Dutch and Portuguese arrived on their shores and started setting up the means to extract that wealth and send most of it back to their home countries! Previously, in our historical texts, we have always been told that India was dirt poor except for a few wealthy maharajas.