Blockchain though decentralized is still under the control of Domains, DNS/Servers, ISPs and its extremely dangerous.
What I mean is:
a) All exchanges(Dex & Fiat) and wallets need domains/DNS/Servers to exist. These are centralized infra which can be used by authorities to shutdown exchanges instantly.
b) 13 ISPs all over the world carry the traffic of all the blockchain nodes, again these ISPs can be asked by any authority to kill all blockchain traffic. Blockchain will come to screeching halt and will be stone dead immediately.
Decentralized web or blockchain can not live under centralized infra. It needs to be absolutely free to grow to its fullest potential for humanity.
Am I wrong? Are their solutions?
You are not describing how to kill cryptos, but how to kill any service out there that runs on the internet. "Any authority" does not exist. Most countries have laws and if one tries to stop cryptos or any service, be sure that some other will make profit from doing the opposite.
I am sure someone more knowledgeable about the internet would be able to give you much better technical reasons. If not... we will always have the Deep Onion coin