Let's take first example. As a bank - why it is in your interest to release that authority to blockchain when you are authority and existing infrastructure exists?
Even banks can be victims of inefficacy or corruption due to too many middle men. Furthermore, they can also have disputes about ownership of loans, property or money. In my country, there is a bank that is actively embracing and supporting blockchain: https://www.abnamro.com/en/about-abnamro/innovation/blockcha...