It's certainly no coincidence that, according to the foreign direct investment statistics, Barbados ranks second or third each year, behind the United States or Great Britain. I've never received an explanation for why Barbados is the country where Canada makes the most foreign direct investments. Apparently, it's very profitable to build hotels in Barbados, which is why so much money is invested in the country.
However, the real reason is as follows, and it's even explained by the lawyers who work in the field and who help companies. Companies conduct foreign trade in countries with low tax rates rather than remaining strictly Canadian companies. The companies open subsidiaries in Barbados for all their foreign trade rather than remaining Canadian companies without subsidiaries anywhere in the world. Companies use the low tax rates in these countries, regardless of whether Canada has information exchange agreements or treaties with the countries.