Here's a man who should know after 40 POCs and 4 projects at the first bank to actually transact over blockchain- otherwise named Distributed Ledger Technology (DLT). 

There are many reasons why the answer is no. 

"Blockchains don’t help one bank maintain a clear view of its relationships with its customers nearly as efficiently as a centralised database would". Simon Taylor of 11:FS

They are too slow and inefficient. 

Neither crypto nor DLT removes the need for a core banking capability. However, to take advantage of crypto or DLT, a modern core is essential. Integration to legacy will reduce benefits to almost 0.

You still need a core banking platform, but using a blockchain or DLT is probably a bad idea. Blockchains work because they are slower than centralised technologies. They help many mutually distrusting actors agree on a set of facts. Blockchains don’t help one bank maintain a clear view of it’s relationships with its customers nearly as efficiently as a centralised database would.

There is a potential for reconciliation; 

DLT solves the fundamental problem of reconciliation in banking i.e. “I need to know what I see is what you see” (and that remains true and hasn’t changed since we agreed it).

Today banks often have to manually reconcile accounts because despite many standards existing, there is a high error rate. Many of the systems used by banks were built decades ago by people no longer working for the bank and those systems have become increasingly complex.

DLT has the potential to change this across a number of assets in 3 to 5 year time frame. If the core systems themselves are up to the task.

Therein is the barrier to blockchain.

Banking core system are the barrier are Taylor list 4 critical success criteria.

1. Core banking that upgrades itself. Why when every bank in a region has the same compliance requirements do they all need to spend 75%+ of tech investment on mandatory/regulatory?
2. A modular architecture that is digital all the way down. This means everything from the ledger itself can be changed, replaced and upgraded.
3. Rethinking the nature of processes. It’s not enough to make banking as it used to exist go faster, it’s time to rethink the processes and work with teams who have a proven track record.
4. Something you don’t have to do all at once. We’ve all see the horror stories in the news of “big bang” migrations gone wrong. How do you start small but win big and can the platform support doing that for you?

As you might expect 11:FS offers a solution so bankers might do worse than follow the link below. If you are an insurer then follow the link to 360Globalnet for your solution. 

PS: I have no personal or business interest in 11:FS. I just thought Simon Taylor's article on the button.