Most organizations looking to make the move into a cloud environment will find that some of their applications and services will not migrate easily – or at all. With this in mind, White Raven rarely will suggest that a customer standardize on a single cloud provider, or to ignore the benefits of self-hosted solutions altogether. There is usually a need for a mix, and it may not be immediately clear where the balance lies.
Check out this @ComputerWorld article for more:
https://www.computerworld.com/article/3192897/cloud-computing/cloud-vs-on-premises-finding-the-right-balance.html