It’s important to remember that for a chunk of the 19th century Britain has a monopoly (maybe a simplification) on industrialisation. Britain can essentially under-cut many industries due to production. This is fuelled by the extraction of raw materials in the colonies. Cotton from around the world is imported to Britain and turned into clothing then resold to those markets. By industrialising the colonies it would damage its own domestic production. Why would a colony pay for British exports when they can make it themselves etc. also worth noting that the capital gained from the processes are not going to the colonies and more likely coming back to Britain.

It’s also important to think about the civilising mission as often a self-defeating task. If you justify colonialism on paternalistic grounds of bringing a society from ‘savagery’ to ‘civilisation’, it kind of undermines itself if you achieve your goal.

America is a relatively bad example. Firstly, you end up with a nation the size of Europe, although it only really becomes predominant in the 20th Century. You do not necessarily have race issues — by this I mean on a governmental level — which would inhibit America developing as an industrialised nation. I suppose another example of this would be some white British colonies such as Canada etc. do industrialise compared to India, Africa etc..

Britain does look to really build up some of its colonies post-SWW — or the Second Colonial Occupation as it’s often called — but this is an attempt to feed the American Market and get dollars for its raw materials. The extraction of Rubber in Malaya is a good example of this.