It will not kill traditional banking now or in the next few years... well, probably in the future (since we cannot close that kind of idea), when the people are ready to welcome innovation and entertain change after they realize that blockchain is a lot better than traditional banking. But it would be really hard since private companies will not tolerate for such change to happen. But as people began to be more fond of digital cryptocurrencies and transaction online without those fees and the bank involved, well probably crypto may kill traditional banking little by little.