Also Lithium ion battery have a fairly fixed ratio of capacity and power, of about 1MW to 1MWh. That makes them expensive for storing large amounts of power. With pump storage you're much more flexible, just build bigger reservoirs. very large pump storage assets can be optimized even seasonally.
With physical energy storage you also don’t need to worry about the environmental effects of lithium nor do you need to worry about charge cycles sure some maintance is required but the majority of the cost is going to be in the reservoir and that can stand for centuries.
