Nothing, unless they aren't interested in being and carrying out the duties of a project manager. "Soft skills" like developing team processes, improving intern

Nothing, unless they aren't interested in being and carrying out the duties of a project manager. "Soft skills" like developing team processes, improving internal documentation, and even helping other engineers on the team can make a different and valuable impact when they're coming from the engineer themself, rather than a PM or engineering manager. Ideally, whatever criteria used for the different rungs of the engineering IC ladder should call these out as contributions that are taken into account.