The heavy machinery with moving parts lifting thousands and thousands of tons is also going to need maintenance and wear&tear replacements. The problem with scale is that all these proposed gravity batteries need much, much more machinery than an equivalent pumped capacity pumped hydro or chemical battery plant.
This is something made easier by the fact that we understand how mechanical designs age. We've built high-standing structures with parts that move in a similar way that last decades. We understand how to maintain those structures without totally replacing them.
