If we are adopting crypto as a global currency, not everyone will be able to survive because the basic necessity to use crypto lies in the ability to use the internet. As of now, the literacy rate is not impressive especially when it comes to the technology and hence not everyone will be able to use cryptocurrencies to transfer the values. That would give big trouble for the entire economy.
Yeah, to using crypto it's need at least basic skill on computer and internet. It will be really annoying, because there are so much people on the world that didn't know computer even internet, even though technology has developed so far.
The situation will definitely improve down the road but as of now, the sharp transformation is not possible due to this limitation. Crypto is based on blockchain technology which relies on the principle of decentralization that is focused on transparency and in order to bring the transparency, there is no other way than using the internet for broadcasting the transactions.