Why does Rock-Type even exist?

It's completely redundant when we have Ground. It's probably the most irrelevant and forgettable typing as well. It serves no purpose now that we have Steel type.

In my opinion Rock-type Pokemon should be retyped as Ground, and Rock type moves should just be removed entirely. Nobody would mourn the loss of this boring typing.

Does anyone here even like Rock-type, aside from smogonfags?