So, impoverishment of colonies is not due mainly to the direct extraction of surplus.
The Leninist theory of superprofits from imperialism is that superprofits are "extra" profits, the icing, not the cake. The theory is not that a major fraction of the total wealth of the imperialist centers comes from the colonies today. To repeat, the idea is not that the exploitation of superprofits impoverishes the exploited nation. It is that the extraprofits give the imperialists extra money to play with in critical matters like buying off the labor lieutenants of capital and other leading sectors of the working class; buying off compradors within the colonial nations.
Charles