The world of technology is evolving every year what if in future a new tech is been born that can kill crypto or works better than crypto won't this kill cryptocurrencies?
Also I heard that super computers can get through all crypto wallet keys easily in a matter of days, true or false?
Unfortunately, no one knows what will happen next. As for new technologies, if we look into the past, we will see that many technologies that were earlier are still being used now. This makes us understand that even if there is a new technology that is better than the blockchain, this does not mean that the blockchain and cryptocurrencies will disappear. I believe that the blockchain and cryptocurrencies will work for as long as their creator laid down, or more precisely, until they complete their task. In any case, I believe that it is too early to talk about the replacement of blockchain and cryptocurrencies.