yes at this time the number of banks that want to use the blockchain is increasing. some banks adopt blockchain because with blockchain technology customer data will be stored securely, operational costs will also be lower and security systems will also be stronger not easily broken into. I think for big banks to use blockchain is quite easy because they have big capital. but for small banks it is quite difficult because they do not have large capital to be able to adopt the blockchain.
Whether the Bank will use blockchain or not, but it will not affect the security system in any way.It is already at a very high level without blockchain.If desired, customer data can also be sold bypassing the blockchain.For me, blockchain in the banking sector in my opinion will help automate many processes that are now performed by a person.