Are we ready to go back to ancient times? I think no, it won't happen. I think there will be better internet technology for now. How difficult would it be if we went back in time all the information was printed and had to have a tangible form? For example, newspapers. Not only crypto, the whole world will feel a loss by losing the internet. Bitcoin is only a small part of the impact, there is a bigger impact if the world is without the internet. It seems impossible, because nowadays the internet has become the main need of every country.
We are currently in the world of technology. The world is moving forward, not backwards. Changes have occurred for the better despite the bad impacts. But that condition will continue. Because people will continue to work on fixing existing technology shortcomings.
Newspapers still exist, regardless of the Internet's success. Many people prefer to read them on top of online articles. Even paper money exists. The world is not fully digitized yet. It's process that will take a long time to materialize.
I get your point that the world is becoming more dependent on the Internet to survive. But it's not an indispensable tool (yet). Oppresive countries can block Internet access to its citizens and carry on as usual. Once the world becomes digitized, such countries will go as far as restricting certain areas of the Internet. Sort of how like China is doing today with the "Great Firewall". But this hasn't stopped people from using a VPN to bypass the firewall. The same can happen with Bitcoin in the future. It will become so popular that it will be truly unstoppable. People will find a way to get access to it regardless of current government restrictions. Even now, it's difficult to take down or limit Bitcoin usage. So long as Bitcoin remains decentralized, there should be nothing to worry about. Just sit back and relax.
