Cryptocurrency aims to create a decentralized monetary system (Unbound, not monopolized by one party). Based on this, the purpose of cryptocurrency itself (if successful) replaces the role of banks in carrying out transactions and payments then the banking will lose customers, fee-based income, and sources of funds that they can take advantage of earlier, Maybe that's one reason why not all countries give go signals for bitcoin
People think that banks will lose out, but that's not the case; just as much as we benefit from all developments related to crypto, banks can as well.
If we look at the global interest of banks in crypto as a whole, mainly due to how exchanges are generating hundreds of millions in revenue every year, and how their clients keep bugging them to start getting involved in crypto, it's just a matter of time before banks start to compete with exchanges and wallet clients. It's the potential income they are after, and that's something they will try to obtain at all cost, that's a certainty right there.
In a way, banks shutting down accounts of clients and exchanges makes sense as well if you think a bit further; it could be seen as very early signs of them trying to get rid of competition, where at a later point when the regulations allow them to enter, they will and start dominating this market. Crypto will force banks to change and to adapt, but not to get rid of them, and we don't need to get rid of them; banks do their thing, we do our thing, it's that simple.