A year ago, some of us were hoping that Venezuelans would have adopted bitcoin as their currency (or an alt). But the rolling electricity blackouts not only mean you can't use credit cards, but you can't use cryptocurrency. So they've gone with old fashioned US dollars in cash.
Yeah, that's one of the big drawbacks of trying to use crypto when SHTF--if there's no power, there's no way to send it unless you can at least keep your cell phone charged, and even then it's not reliable.
But it doesn't surprise me that Venezuelans opted to go with the USD as a replacement currency. A few other South American countries have been using it as a backup currency for a long time anyway. I've heard that most of the use those dollar coins see that the US mint keeps making is down in S. America, and I heard that well before the crisis in Venezuela.
As an aside, I watched a few Youtube videos dealing with Dash and their foundation's attempt to bring Dash to Venezuela. They made it seem as if they were doing a decent job of getting the citizens to start using it, but I still had no doubt that no cryptocurrency would gain as much popularity as the USD. You really need physical cash when there's a crisis, and there's no getting around that fact.