If someone started with a hill or mountain at an almost suitable grade, then what they dug out to grade the slope properly could be put in second hand shipping containers at the top of a hill. Bring the containers up or down one at a time to get the power in or out.
Maybe have some one site solar or wind generation to try to bring and extra container up every once in a while.
People generally don't want steep slopes for much anyway so even the property ought to be cheap, it could even be municipal property for maximum cheapness.
The hardest part of any of this is the all electric trains with efficient regenerative brakes.
But a dry system, relying on weights? There isn't a material that is dense enough to make it worthwhile. Even a boxcar full of granite would need to be orders of magnitude heavier than it is for gravity storage to be economically useful.
There is merit to lifting large loads like this, but IMHO they should be concentrating on weight instead of distance. Which basically takes us back to pumped hydro because we just don't have anything on the order of a million tons or more that can be moved cheaply and easily. I could maybe see a large carpet rolling a layer of sand or stones up into a cinnamon roll so it's self supporting. Probably not the safest place to stand under though!