You can also think that banks can start offering their customers bitcoin and crypto if their central banks allow it. Compare bitcoin to fiat and not bank. Also bitcoin is an alternative to fiat and not a replacement. Just know that bitcoin can not replace bank at all. Also it can not replace fiat but you can use it as alternative.
Exactly, Bitcoin can serve as an alternative but not a replacement even it it's adopted by the central bank, Bitcoin value can fluctuate,market not stable, can fall or rise,, depending on different situation cannot easily predict it's store of value, and also security of fund can not be totally assured as cyber criminals always target crypto platforms as they have high value assets which is the coin, and movement cannot be easily tracked,, but if traditional banks are able to put in place systems or platform that can effectively cut off the inadequacies of operating with crypto, it will go along way helping the adoption and also increase the trust in the use of bitcoins as a media for transactions and other financial actions.