For the Europeans, who moved there. The original inhabitants might think different. In their point of view, these colonies actually were the most devastating.
But leaving aside whether the advantages accrued to one ethnic group or another, didn't colonization increase the economic output on those land masses?
Overall, I mean (unquestionably it was destructive too).
I can speak about India. India went from controlling 25% of the world's output in the 1500s to controlling 2% of the world's output in 1947. Till about 1900, Indians were banned from starting industries. Just so that you don't think that Indians had no industries, the first Fellow of the Royal Society from India was a shipbuilder [1]. British colonization was devastating for Indian commerce. You can argue that it is only now hobbling back to normalcy.
On balance, British did introduce railways, which was instrumental in unifying the country, and a unified legal system.
