Technology developed as a result of brains and a society willing to both fund and develop scientific advances. There was no industrial revolution in any part of Africa. Iron smelting was very limited and had no expansion in precolonial times. The entire structure of the indigenous cultures did not lend its self an equivalent progression. Life developed along very different lines compared to Europe and especially the UK.
It was far more than the close proximity of natural resources that kicked off development at coalbrookdale and concurrently lead to harnessing steam and developing machinery and factories. The other part of the story was the "emergence of a pro-science, commercially rich, high-wage society guaranteed by a benign, non-authoritarian government which allowed liberty and free-trade" A third factor was the earlier formation of the Royal Society, the very first ‘learned society’ meeting on 28 November 1660 followed a lecture at Gresham College by Christopher Wren. Joined by other leading polymaths including Robert Boyle and John Wilkins, the group soon received royal approval, and from 1663 it would be known as 'The Royal Society of London for Improving Natural Knowledge'. A fourth factor was the development and growth of banks.
Other European societies jumped on the bandwagon and the race was on.
Perhaps it was a unique set of circumstances in England that gave the means to harness nature and go on to carve out an empire.
Whatever it was, indigenous societies elsewhere were outclassed, outgunned and out out-maneuvered and the pillaging started.

The modern equivalents are multinationals!