Consider the new Swiss Lake Mutt pumped hydro plant. Should we be building more of them? Can we?
In UK, pumped hydro has never been used as an energy storage feature. I mean it's purpose is not to store energy. Energy storage is just something it does in order to work. UK pumped hydro is used to meet peak demand. Because hydro "switches" electricity onto the grid faster than anything else can. We face peak demand every day so the capital is always in use and the plant provides the grid with electricity every day (so gets revenue daily).
RE advocates don't seem to get this. UK pumped hydro was very expensive to build but eventually pays for itself because it's constantly used. RE advocates talk of pumped hydro as an energy store mechanism to alleviate unreliables. If so, capital plant will not be constantly in use. Unless pumped hydro is regularly making money by selling electricity to the grid, it won't make economic sense.
That's probably the reason RE advocates want the grid itself to pay for storage. If the grid has to pay, existing fossil plant like gas will be paying to put its competitor (peaking provider) in place!
Technically speaking - I'm not sure that UK pumped hydro ever did pay for itself. It was built when the UK grid was one nationalized company. Their accounting systems were bizarre to most outsiders. Indeed - bad accounts - is the reason nuclear became unpopular with UK politicians in the 1990s as the grid was privatised and many of the nuclear plants (Magnox reactors) were impossible to privatise. The effect of impossible accounting on politicians is revealed in Simon Taylor's "Fall and Rise of Nuclear Power in Britain".