That is utterly nonsensical. Are there HUGE tracts of land where 100 ton railcars or concrete blocks grow on trees? If not, then how are you getting them there

That is utterly nonsensical. Are there HUGE tracts of land where 100 ton railcars or concrete blocks grow on trees? If not, then how are you getting them there? On a per-mass basis what do you think is easier to transport, railcars or water? Transporting adequate amounts of gravity storage medium is not at all a competitive advantage for non-hydro gravity storage. For that matter, it does not even constitute a meaningful factor except as a disqualifying one for the nonsensical ideas people somehow seem to get funded.