I get the feeling that governments would be able to shut down decentralized networks anyway. Remember, they are governments. Resources are more like a way of counting for them, not a limiting factor.
All they have to do is give ISPs the order to block out certain data transactions and voila, it is all gone. I remember at university people had their internet connections blocked for using BitTorrent. That was only a University IT department doing it, not a full blown government!
For the moment, while governments are not stopping cryptocurrencies and so on, then decentralized crytpocurrencies are safe so long as the developers want them to be. If everyone is running your software without question then it should be quite easy to insert bugs which give you centralized control. Even if you don't want to, accidental bugs can lead to significant lacks of safety.
Many projects put their codes on github, but I wonder if this is really relevant. Most people can't read code and most don't bother to read code that isn't their own.
Crypto is safe for the moment because of the philosophy of crypto, and nothing else. But for now it is enough