The vast majority of the colonial theft and exploitation came
after industrialization, and as a
result of it. Once you're 10x wealthier and more technologically advanced than the rest of the world, it will be conquered, one way or another.
And while individuals got very rich from colonizing, and rulers got much pride from ruling vast new lands, the colonizing societies as a whole did not really get richer from it. There are benefits from colonies, but there are also costs.
Of course, Spain and Portugal did build vast preindustrial colonial empires in the New World. Not by being (very) much more advanced, but mostly by the incredible luck of having much better immune systems! The fact that 80-90% of the New World people just spontaneously died on encountering Europeans, for reasons none of the sides understood, is one of the most astonishing events in history to me!!
So they (mostly Spain) had a few centuries of weird prosperity in mountains of gold and silver, while still having a primitive mercantilist economy. Once capitalism and the industrial revolution started elsewhere, they were left in the dust, their pretty metal stashes no match for liberated human ingenuity.
You do ask a good question. Why did the stars align in 1760s England, and not in the several other places in history that seemingly had most of the ingredients? I've seen it asked a few times, and never answered. I won't pretend that I, some random programmer with opinions on a web forum while eating breakfast, have the answer either...