Let's get something clear here guys, banks are the custodians of fiat (government approved currency ) while cryptocurrencies are digital currencies which transactions are recorded, verified and maintained by decentralized system using cryptography. Therefore cryptography can be liken to a digital bank.
The reason why most people might prefer fiat or rather commercial bank for their savings to cryptography is its volatility. However both serve almost the same purpose; medium of exchange for goods and services.
Your explanation is quite direct in this regard because you have also explained the differences between the two and the similarities between the two through almost similar goals. However, over time, most people have also chosen cryptography for their investment, although they also do not stay away from conventional banks because they may still be needed to store some of their fiat. But as for the problem of using both of them, I personally still use them very often because up to now there have been no problems that have prevented me from continuing to use both of them.