Energy density is terrible of pumped hydro, plus you have the environmental impact; tunnel out the inside of a mountain, place a generator hall in there, and then flood a valley. Sure it look ok at the end of it, but huge damage has to be done each time. All of that coats large sums of money too, and it can only be done in a relatively small number of locations. Step 1. You need a mountain to pump the water up.

Compressed air batteries are a lot more energy dense, so smaller footprint, so much lower environmental Impact / cheaper and they don’t rely on particular geographic features to work. They might be a bit less efficient, but that seems like a good trade to me.