Pumped Hydro have huge capital work costs and sit behind transmission system barriers often, but they can go on and on and on. They have a startup delay component. They have lower overall efficiency because of pump losses (don't over cost this, often the power used is marginal, or was going to waste anyway)

So whilst its a valid Question as written, it is a bit apples and bicycles comparison: they don't actually "equal" each other in how they respond, and for how long, and what associated outcomes are alongside.

I believe the Turnbull Snowy pumped Hydro is $2b+ of cost to dig new tunnels and is 5+ years off. the same investment at current prices ($150m for the neoen stack) means TEN of them could be deployed at the rate Tesla can supply batteries, inside the five year window. Arguably better use of the money but the $2b gives a huge amount more sustained power.