Pumped hydro storage only holds about 8-12 hours of power. To be economically viable to build you need to cycle it daily.

It uses enormous amounts of land and capital to build, and is ongoingly dangerous in a unique way. If LiFePO4 can do 4 hours at full output already, and be placed anywhere using volume manufacturing to expand, then batteries are straight up better.

Pumped hydro is an expensive dead end.