Britain has never shown the slightest interest in the lives of the people of countries we trade with

Even if that were true, they will be able to sell their produce in our market without tariff barriers against them. That will improve their lives.

Wiki, "The fair trade movement is popular in the UK, where there are 500 Fairtrade towns, 118 universities, over 6,000 churches, and over 4,000 UK schools registered in the Fairtrade Schools Scheme"