Bitcoin can't be killed. It just will continue in other parts of the world... Bitcoin as currency is even officially listed at the US exchanges, see for example this: https://finance.yahoo.com/quote/BTC-USD It has a Market Cap of 964.723B, ie. almost 1 trillion USD. This is not small... There's even a Bitcoin ETF in the US: https://finance.yahoo.com/quote/BITO
But then just own & trade it in a foreign country, and keep it secret... Pay a poor foreign local so that you can use his/her name for your such secret private business activities... Of course just joking, never do any illegal shaete, man! Dog and cat partners in crime:
Banning Bitcoin is like trying to ban the Bible. You can outlaw it but the people who really believe in it will just move to a jurisdiction where it's not banned. We've already seen that happen in China. They banned it and the miners and others in the industry just packed up and moved all the equipment to the U.S. and other locations where it's legal to do business.
The Bitcoin community is well aware of the supposed threats by quantum computing. First of all, the current quantum computing technology isn't even faster or better than the current ASIC machines used to mine bitcoin in the first place. Many experts think it will be at least two decades before the quantum threat is even realistic. Second, keep in mind that some of the smartest people on the planet are involved in the underlying bitcoin software, and post-quantum encryption planning is already in process and is easily implemented through a soft fork. So the belief that quantum computers will be able to just come in and easily steal all of the bitcoin overnight is over-simplistic and more in the realm of fantasy land.
That is hard to believe. Smart people recognize that often times it is easier to knock over a house and start to build a new one instead of repairing and fixing the old house here, there and everywhere. Or build a new wing at least (fork analogy) As I mentioned earlier, Litecoin was already an improvement over Bitcoin and it took an hour to create it for 1 person. And that was a decade ago, so if what you said was true, cryptos should be perfect by now. The real issue isn't the smartness of the tech people, but recognizing the blockchain trilemma that simply can not be solved by the smartest people of universe. Fast, secure, scalable, you can choose only 2: (just like your car mechanic's work: fast, cheap or good) https://www.gemini.com/cryptopedia/blockchain-trilemma-decentralization-scalability-definition