Dispatch time, total installed capacity, and regional power grids.

Batteries have a much faster dispatch time than pumped storage. Pumped storage is good for offsetting reduction in other production capacity, and its dispatch time is faster than peaker plants, but its not as fast as a battery.

https://en.wikipedia.org/wiki/Hydroelectric_power_in_the_Uni...

https://www.eia.gov/todayinenergy/detail.php?id=41833

2020 numbers had 22,894 MW of capacity. More storage capacity for power is needed.

The "where are things located" is in the mountains where there's a significant elevation change. Most of the country is too flat to have pumped storage be practical. Installed pumped storage in Michigan (about 2GW of capacity there) does little for the power demands of North Dakota.

And then... there's also building new ones.

    Even though FERC has issued licenses for three proposed pumped storage projects since 2014, no new pumped storage projects have come online in the United States since 2012. EIA’s most recent survey of planned power plant additions shows no pumped storage projects under development.

That may be in part from the 2005 failure at Taum Sauk. https://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_...

    At 5:12 a.m. on December 14, 2005, the northwest side of the upper reservoir was overtopped when water continued to be pumped from the lower reservoir after the upper was full. This led to the catastrophic failure of a triangular section of the reservoir wall and the release of 1 billion US gallons (3,800,000 m3) of water in 12 minutes. 

   ...

   As of 2011, Ameren was reported to have paid a total of close to US$200 million in settlements related to the 2005 breach.