Blocking water with a dam is a well understood problem. Don't bother with wind nor solar nor nuclear nor storage. Just build dams, problem solved.
I feel like we still have some problems with dam building, because they keep failing. We struggle to get the building material (in particular, sand). Concrete is pretty awful in terms of CO2. Dams of all sizes cause problematic changes to the rivers they're on, and block flows of fish and other animals. Smaller low head weirs and dams kill humans.
Lots of time, money, and effort is going into removing smaller dams and low head weirs.
Look at the countries that produce all or nearly all their electricity from renewables. It's dominated by hydroelectricity: https://en.wikipedia.org/wiki/List_of_countries_by_renewable...
And since it's a well understood problem we can just build it everywhere, in arbitrary quantities.
And you need a reservoir down below to receive the water as it passes through turbines otherwise you're waiting for rainfall to fill that upper reservoir up naturally.
The geographic conditions to make pumped hydro are far more constrained than you seem to think. Most water reservoirs for municipal water supplies don't have the elevation drop to be used for generation and they don't have the lower reservoir to capture and feed water back into the upper reservoir.