The issue is the amount of storage required. It depends a lot on the country, but here in Germany I think everybody agrees that we need to store enough energy to power the whole country for at least 2 weeks before we can get rid of fossil fuels. That's a lot of batteries. And currently there's not enough storage for a single hour...
In these dimensions, resource availability becomes a limiting factor. Pumped hydro requires a lot of space and geography that many countries can't provide. It may be an option for Norway or Austria, but not for Germany. And even if Germany would buy the planned world production of lithium batteries for the next 10 years, we still wouldn't have enough. The math just doesn't work out for both. Hydrogen looks more realistic, but is not a mature technology at the required scale.
In these dimensions, resource availability becomes a limiting factor. Pumped hydro requires a lot of space and geography that many countries can't provide. It may be an option for Norway or Austria, but not for Germany. And even if Germany would buy the planned world production of lithium batteries for the next 10 years, we still wouldn't have enough. The math just doesn't work out for both. Hydrogen looks more realistic, but is not a mature technology at the required scale.