Cryptocurrency network is functional through internet connectivity, some form of offline access is possible, but the same is limited. The internet too gets advanced with time, and the next important thing is the mining process which is the backbone to the cryptocurrency network. So, global government crackdown cannot collapse bitcoin.
That's certainly true, mate. Bitcoin is largely flexible as a cryptocurrency providing the means to run it either online or offline. Thanks to its open and decentralized design, anyone can support the Bitcoin blockchain in many ways. Considering all the time that has passed since Bitcoin's inception, it has become harder for governments to act against it. As such, the least they could do is to tax and try to regulate Bitcoin for mainstream use.
Still, if a global government crackdown takes place, people will figure out a way to continue using Bitcoin secretly. Nowadays, all of this is possible with the inception of Tor and i2p. Anonymous and private networks, will serve as the basis for cryptocurrencies if something like this happens.
Nonetheless, everything depends whenever governments are deeply interested in letting Bitcoin grow or all the way around it. Just my opinion