Mughal India was roughly 20–25% of global output. It was British colonial rule that exploited and stole insane amounts of wealth and led to India’s economic decline. Comparing centuries of complex Indo-Hindu-Muslim history with British colonial occupation and extraction makes no sense.
Some Muslim dynasties began through conquest, as many dynasties throughout Indian history did. But over centuries, Muslims integrated, intermarried, adopted local languages and customs, and became part of Indian society. Muslim-ruled states relied heavily on Hindu generals, officials, and allies, and their wars were largely fought over territory and power, not as some continuous occupation or religious war against Hindus.
Indian Islam is not a foreign invasion that destroyed. Indian Muslims are indigenous to India, and their ancestors converted for many reasons, including Sufi influence, social mobility, and escape from caste discrimination.