The government of Venezuela has no reason to replace a currency they control with one they don't. Switching to cryptocurrencies will definitely not solve the many systemic issues in Venezuela so the government would still end up with a broken economy and on top of that they wouldn't control the currency anymore. That doesn't make sense. Switching to bitcoin won't make the Brent price go up.

The people could individually decide to switch to cryptocurrencies (or dollars, euros, bottle caps etc...) and get others to accept it but then you have the problem of purchasing this currency in the first place and it still doesn't solve the underlying issue of the broken Venezuelan economy. You could be a bitcoin billionaire in Caracas right now, if the shop doesn't sell toilet paper then it doesn't sell toilet paper. On the other hand if you have bolivar bills...

It's not the bolivar that's broken, it's the Venezuelan economy. This ridiculous inflation is a symptom.