Bunch of large holes in your ‘theory’ here. Black people and there communities have been living in America for over 400 continuous years. Canada for less than that. Caribbeans first migrated to Europe and the UK in the 1950s and 60s. The experiences, reactions and purposes for being on each side differ radically. The original intent of migrants travelling from the islands to the UK was to earn money, increase their opportunities, and return to the Caribbean. There’s a general rejection to the idea of full integration for many that made the journey which extends to their descendants. For black people in America “this is it.” What they have there is what they have. There is no dream or psychology of living out of a suitcase until they sail off back to “their” sunset, whether it truly exists as they remember/imagine it or not. This then partially informs on why the black movements for full integration, equality and acceptance carried the determination and intensity it had. Blacks in America are Moses if the seas didn’t part, with all that that entails. It’s a completely different dynamic.

The other aspect you’re missing is survivorship bias. If the plan is to make money and return to the caribbean, you have to include the fact you’re not looking at those that succeeded, or even just one aspect of the livelihood of those who did