The things are not about American junk food or overvalued brands. With this embargo, the US government deters other countries from trading with Cuba, cutting it off from an international payment system, imposing restrictions on ships going in and out of Cuban ports, and punishing firms that may deal with the Cuban government (of course, any one of them can be accused of that). Hence, there is almost no one on the international market who wants to deal with Cuba. Because the size of its internal market isn't worth a risk of American sanctions. As a result, Cuba has severe shortages even in food and medicine, to say nothing about other things.