In your view, what does this mean? The distinction seems important to you, but I am not sure if you have really gotten into the meaningful difference. If it is definitely not a blockade, and that is important to say, why is it important? Does it mean we should view the situation differently? Does it imply more/less culpability to one party or the other? Should we have more hope around the humanitarian crisis? Or less?

Being direct about these kinds of questions would maybe help us understand where you are coming from here.

A blockade is an act of war, carried out by military force. Saying the US is blockading Cuba is saying that the US and Cuba are at war. That alone is a pretty big reason to understand the difference between a blockade and an embargo.

The other important dimension is that countries participating in the embargo are choosing to participate in the embargo. This is distinct from a blockade which is done unilaterally. The Royal Navy didn't let ships into Germany ports during WW1 if they paid a tariff. No, they seized ships bound for Germany, because that was an actual blockade.

An embargo is when countries decline to trade with you on their own accord.

A blockade is when a country uses military force to physically stop other countries from trading with you, even if those other countries want to trade with you.

They're pretty substantially different.