Not many years ago people got paid to, among other things, pick out the appropriate operating system for any given application. Clearly there's not much of a future in that.
These days that same person is responsible for vetting cloud hosting providers, email service providers, and has to be capable of comparing the "old" in-house solutions and bring things inward if there's benefit.
The technology changes, but the role more or less stays the same. The system admin is generally a bridge between business operations and the technology stack, and there's always going to be glue there, particularly for businesses of at least 10 people.
Disclosure: System Admin / Engineer by trade. Weigh my opinions appropriately.