Cuba trades with other countries worldwide, its economic problems are not caused solely by US sanctions. Cuba’s terrible economy and widespread poverty are two-fold. Firstly, the centrally planned communist economy has been a failure in Cuba as it has elsewhere. Secondly, the widespread corruption which is inevitable in a one-party state has led to government officials keeping much of Cuba’s revenue for themselves and for personal vanity projects.
Humanitarian aid has also long been established to prevent too much suffering to the Cuban people. Most recently the US has offered aid in the wake of the coronavirus.
The Cuban regime seeks to blame the US for its failing economy. The US has attempted to alleviate the worst of the problems the embargo has caused.