The country itself is poor, because of the blockade. If the US would let private companies trade with them and with the cubans freely, they wouldn't be poor.
But no, we hold Cuba to a standard that no country on Earth has achieved. Maybe except for the Germans, since Merkel is keen on doing her own groceries.
> The Castro family can travel the world and enjoy a lavish lifestyle
But not if you finish the sentence:
> while most of the population lives in poverty and are not allowed to leave the country.