So the previous comment was quite accurate. The Mughals of Babur were far removed from the Mughals of Bahadur II.
People were glad to get rid of them and their wars which crippled India.
Britain kicked them out and (mostly) unified India.
Not to say I have any idea what would have happened without colonialism, but thinking that India would have retained their share of world GDP is naive.
Owning India is what allowed Britain to fund its own development (as well as all its international wars). The british destroyed india's local textile sector (which was world-famous), shipped all the cotton to Britain, and sold clothes BACK to Indians. That's how this industrial revolution happened.
This is what Mahatma Gandhi opposed and encouraged Indians to make their own yarn. That's where his association with the "charkha" and swadeshi movement comes from.
Just to be clear, I'm not saying pace of development wasn't seriously set back through colonialism, I'm questioning specifically this percentage of GDP argument.
If India wasn't a colony, wealth would not have concentrated in GB, likely slowing Down their development and Maybe even making them more open to local conflicts.
Provided the French or Dutch didn't conquer more of India, and, it's hard to argue that wealth remaining in India would have not have resulted in more trade and local development.
We can definitely say that having someone come to your country, and clearly stop you from building the best product you can build, sell or pruchase, impoverishes your country.
You can see in Russia, in the absence of any colonialism, the enormous struggle which there was to transform an economy dependent on manual labour, and with an elite dependent on feudal social structures, into a modern economy. I would separate the issues of abuses/crimes and the issues of development in the sense that the abuses were perpetrated due to moral failings, of power-hunger, racism, and greed, but development is not just about morality, it's about having the right policy and the right trajectory for society. In terms of development, the really damaging attitude was that India's ancient culture should not be disturbed to make way for industrialization, and this was an opinion shared by many well-meaning British and also Indians, pre and post independence.