It doesn't address the problem of Venezuela at scale: the initial distribution problem. If you trade BTC for Bolivars between people in Venezuela then the total number of Bolivars, hence welfare within the system, remains unchanged. If you trade Bolivars for things outside, you can trade outside the country, and are better off with literally anything you can get outside the country.

I don't doubt for a small handful of people who got their hands on some BTC they individually are better off. That doesn't change the fact it's not a reasonable solution at scale.