energy storage (e.g., batteries)
Energy storage isn't batteries.
The phrase "e.g." means "for example" and is used to describe a subset of the previous term. It doesn't need to mean the exact same thing.
We can say things like "humans consume resources (e.g., fresh water)" and that would be a valid sentence.
Plus it's fair to expect that in the next 10 years, the vast majority of grid scale energy storage worldwide is going to be electrical batteries. Gravity storage just can't compete except in very limited geographical and geological circumstances.