On the credit side, it's seen as having drawn peripheral lands into international commerce, ended (mostly) practices like slavery and harmful rituals, established a rudimentary system of western schooling and later governance, and imposed some degree of peace, though often after initial violent conquest.

On the debit side, it geared subject economies to low value-added primary production for European markets, stifled nascent local industrial growth (at least for a time) and deprived the ruled peoples of control of their political future, even sometimes creating fragile states with no real foundation. Except in white settler colonies, investment limped along at paltry levels. Traditional elites were compromised or corrupted while potential modern national leaders were exiled, imprisoned or sometimes killed.

The great deeds are gone but the consequences of political exclusion, economic subjection and arbitrary polities are still with us. Colonialism isn't for the benefit of the governed, and on balance it lived up to that.