I believe that banks do not accept cryptocurrency as they are two different systems and they cannot exist with each other. At the same time, there is a struggle between banks and cryptocurrencies, and if suddenly banks start accepting cryptocurrencies, it means that the current financial system is gone and another system came instead. But now it is too early to say, since it is not yet clear who will win this battle, bankers or digital devices.
Sooner or later, banks will still have to work with crypt currency, this is inevitable, which means they need a condition under which the crypt currency will evaluate financial assets as the dollar does now. I believe that both systems will work depending on each other. If now the young decentralized one depends on the centralized one, then in the future everything will be the other way around.