1. Stats are stats. If Cuba, even while facing a crisis in its food production due to lack of seeds, gas, and fertilizer, is still able to feed its people better than its neighboring countries, then that is a stirring indictment of capitalism.

2. Both of your examples link to a drop in imports as the cause of shortages, itself a symptom of the ongoing global production crises caused by COVID-19. A wealthy country like the USA can paper over a problem like that by throwing around money and credit - a small country like Cuba can't.

Consider how Cuba's economy could possibly respond differently to this situation if it were capitalist. I suppose they could take massive IMF loans in order to shore up imports, at the cost of "structural adjustments" that cause untold damage to future generations by eliminating the government's mandate to run public services - but that plan hasn't exactly worked in the long term anywhere it has been tried.

The fact is that these crises are well outside the sphere of influence of Cuba's economy or government, and are exacerbated by American imperialism against Cuba and its allies (ie literally hijacking Venezuelan oil shipments using the US Navy). Regardless of political ideology or economic policy, Cuba would be facing these crises one way or the other, and centrally planned communism has proven time and time again that even if it's not perfect it's better at navigating these problems than a competitive market capitalist system is.