Beginning with the fact that cryptocurrency was originally built in some sort as a mean to avoid banks and the bureacracy related to those kind of thing, is there any use for bank to launch their crypto, why would people who are searching for a non-centralized way to manage their asset to join centralization expert like JPM or other
They're likely not targeting the people who actually care about decentralization anyways.
What bank-backed cryptocurrencies are in essence are just an easier way to account for the liabilities of a bank. Moving these accounts off a centralized database and onto the blockchain could result in benefits like security and reduced costs for the bank, not to mention that they can take advantage of the buzz around crypto.
Also, it's very likely that in the future banks will increasingly be utilizing blockchain technology in a centralized manner, especially in the case of backed tokens that only have their value derived from a bank's assets. These should co-exist alongside bitcoin, and have differing usage cases that don't necessarily have to conflict.