Actually, tropical climate is great for growing a lot of stuff. Plants love year-round sun and high temperatures. It’s that countries in the tropical belt have historically been colonised and underdeveloped (overexploited), their colonial owners growing monoculture crops, exploiting natural riches or using the warmth for tourism and leisure. The populations of those countries have been natives that have been killed off to be replaced by African slaves (who were kept uneducated) and European masters (who had no interest in calling the colonial territories home and were interested in sending wealth back to Europe).

While not strictly about Cuba, Open Veins of Latin America is a great book that goes into detail of the level of exploitation of the South American continent. https://library.uniteddiversity.coop/More_Books_and_Reports/Open_Veins_of_Latin_America.pdf