> Didn't the Empire go through a lot of trouble to end the slave trade
Combating slavery gave the British Empire a comparative advantage, as they could export commodities like Sugar, Cotton, Palm Oil, and Coffee from the British Raj (which in the 19th century included all of South Asia as well as Malaysia) and British Egypt (cotton) without a plantation slavery model, while undermining competitors like the US and Brazil who used that model for commodity exports.
Same reason why the industrial Northeast and small-farmer Midwest was opposed to slavery, as both lobbies were undermined by the economics of slavery.
Combating slavery gave the British Empire a comparative advantage, as they could export commodities like Sugar, Cotton, Palm Oil, and Coffee from the British Raj (which in the 19th century included all of South Asia as well as Malaysia) and British Egypt (cotton) without a plantation slavery model, while undermining competitors like the US and Brazil who used that model for commodity exports.
Same reason why the industrial Northeast and small-farmer Midwest was opposed to slavery, as both lobbies were undermined by the economics of slavery.