Am i missing something, or is this useless when you want to refer to an equation from "the past"? I find myself doing that often. For example a methods section

Am i missing something, or is this useless when you want to refer to an equation from "the past"? I find myself doing that often. For example a methods section might pose an optimization problem, then the experiments section a page or two later says "we solve the optimization `\eqref{main-problem}` using Solver X".