vSphere already comes with very rich and built-in automation functionality. Initially, all this was added to make the administrators lives easier. Ultimately it was meant to ease the daily operation of medium and large vSphere deployments. Over time, the SDDC evolved and brought up new possibilities to deploy workloads in a vSphere environment.
With this new possibility also requirements are raised regarding basic SLAs like tiering, performance classes, security, and so on.
For the SDDC, the features which made the vSphere administrators live easier have become a huge time saver for any SDDC deployment. Think about the effort savings you get by using all of this automation vSphere provides per default.
These functionalities can save weeks of custom workflow scripting or implementation work. Just remember that VMware's engineers spent a fair amount of time developing all their functionality to blend in perfectly in the vSphere environment. DRS, Storage DRS, vMotion...