Bitcoin is not a stable coin, suppose they change to bitcoin and in one day bitcoin price collapse. Then the economy collapses badly.
You do not seem to realize they are currently experiencing hyperinflation. Even if BTC goes down in dollar terms it is still probably gaining strength in Venezuela's currency. BTC would be much more stable and save wealth than VEF at this point, without a doubt.
I know but even in that case BTC is not trustable, another problem for BTC is that it is an electronic currency and they needs lots of infrastructures for using it and also the price change in seconds so in different hours of a day for buying a kilo of potato people must pay different amounts of bitcoin.