Why would a CBDC (Central Bank Digital Currency) be good for the economy?
There is good summary (with references) of the benefits of CBDCs on Wikipedia.
With respect to banking sector disruption see this 2018 report by the Sveriges Riksbank. It finds that

while a given outflow of retail deposits into e-krona
reduces banks’ liquidity portfolios and worsens their funding
profiles, banks can normally control this outflow via deposit rates.
Banks can also issue more market funding to restore their liquidity
and funding profiles.

That said,

The exact features of an e-krona can, however, be controlled by the
policy maker. In sum, we do not find any decisive argument against the
issuance of an e-krona when studying financial stability effects on
banks.