re: Legacy of the British Empire

The British Empire was both a generator of the Enlightenment as much as a purveyor of it. The world is a vastly better place as a result of the Pax Britania.

For one thing, slavery would likely still be widespread globally without it. The British Empire is the number one force for abolition in all of human history. By a huge measure

Commerce bred affluence and freedom. Economic growth, combined with certain universal developments- standardized time, weights/measures, gold standard, etc was a unique revolution in humanity.
Most British colonies released after the World Wars are in a far worse place now than they were under the Empire.

The post WW2 Pax Americana is a direct carryover from British hegemony. Western modernity was nurtured and protected by this phenomenon.

The 19th and 20th centuries were a Golden Age of humanity. Those unaware of this fact may be about to see how true it is. You don't know what ya got til it's gone.