Question

why did the company start using the vast resources of Bengal

Answer 1

because it give us good resource

Answer 2

Bengal was an ideal destination for setting up the East India Company for its vast resources.

In the years between 1760–1800, Bengal's the money supply Bengal was hugely reduced. In the 1750s, cotton and silk were exported from India to the European, Asian, and African markets.

By the second half of the 19th century, raw materials like raw cotton, opium, and indigo were the major export items from India.

In the later half of the  18th century, the  British cotton mill industry began to lobby the government to both tax Indian imports and enable them access to markets in India.

For all these reasons the Company started using the vast resources of Bengal.