I think we do't need any central banks for the crypto currency and for the market regulations is 50 50 because if controlled then may be the price is stable and some people will prefer this and central banks are important because people trust it more.
crypto is independent, so I don't think there is a need for a central bank. crypto has many features that allow it to be independent. even if crypto works with the bank and becomes more stable I feel the crypto characteristic disappears. because what I know, crypto is an investment that can be very profitable because of its unstable value.