For some context, Shah Jahan is best known outside India as the king who commissioned and spent his fortune on the Taj Mahal.
The description in the review drives home how when the British arrived, India was about a third of world GDP, Britain, not so much.
India's GDP share was much higher before the invading Mughal invasion started so they were part of the problem. See Angus Madison's historical list of the ten largest countries by GDP.
Silliness actually lies in your knee jerk reaction.
And for all that, London, at the height of British power, had pollution so bad that it was unlivable, in the colder months the smog could choke you out it was so dense. Because they had people living in such close conditions, hygiene was non-existent, and only the rich were able to avoid the putrid underbelly of the working-class city. Well, I happen to know of some other cities with booming populations at the beginnings of industrial capitalism that may have the same problems...I don't live in India myself, but I would say most Indians would be happy if the GDP was cut in half, if they could have clean air and drinking water. But if its all about GDP, then I guess the British are in many ways responsible for lowering the overall "GDP" of 18th century South Asian countries (there was no India until the British showed up, and even before partition it was just called "Hindustan"). But the great industries of India today, and the conditions of working people, that has nothing to do with the British, even though it matters far more than how some Raj lived 300 years ago.