One day banks will accept Bitcoin as medium of exchange and accept deposits from bitcoiners. As soon as the world powers accept it as medium of exchange.
Possible if it will push, but accept the fact that crypto-depositors need to undergo KYC.
Why? There's a situation called "chargeback". Banks can't settle a dispute once it has been filed by their customer if another party is anonymous.
Why make things complicated? That's why there are crypto-exchanges or platforms. No need to cross over.