Like with every colonial power, the empire wasn't there to enrich the entire country or the average people, it was enriching the crown and wealthy business magnates involved in the trade, basically the top 1%, the rest were left to wallow in poverty and hard labor.

I definitely agree there were some individuals who made money from the imperial project, but it wasn't rational at the level of the British state/monarch.

> Like with every colonial power...

Some colonial powers may have genuinely increased the wealth of the imperial state. The Spanish and Mongol empires stand out in my mind here, although I don't have a precise source of accounting.