Consider just Canada alone, from which Cuba could have had any technology they wished.
Given they haven't gotten it, I suspect it's more complex than that! Part of it may be that companies that operate in violation of U.S. embargoes cannot do business in the U.S., thus making Cuba not worth their attention might be part of it.
Change has to come from Cuban leadership, if at all.
Indeed, when dealing with a regime on the wrong side of an embargo or blockade, it's always the one at the bottom of the power slope that is responsible, right?
What is very telling is that the cuban community in Florida is really, really angry we are lifting the embargo - because all it does is empower the people that made Cuba what it is today.
They're angry because their property was seized - but their kids don't generally care. On the other hand, the Cuban government released a bunch of political prisoners in the past week or two, which at least suggests that Raul and the party are at least cognizant of the changes coming down the pipe.