Earlier quoted context omitted.
You should find out what India's share of world GDP and trade was when the british arrived.
Every serious economic paper I've read on the subject suggests that decline in Indian GDP during the colonial years was due to the bottom dropping out of several commodities markets. You seem to be insinuating something else was at work. Do you have anything you could cite?
People were glad to get rid of them and their wars which crippled India.
Britain kicked them out and (mostly) unified India.