Okay, here's my thing: what we tend to call "management" in our field is at least several separate skills. Mostly it's at least technical decision leadership, personnel management and project management. Expecting all of these skills to manifest spontaneously (let alone simultaneously) in one person is absurd.
The best orgs I've seen approach something I'd call a "growth mindset" (or maybe "support mindset"). They identify early potential, encourage (and meaningfully subsidize) skill development, and field-test to validate.
If I'm right about any of this (and, of course, I think I am), then the best growth-oriented orgs are making a huge mistake by strictly separating people into buckets labeled "manager" and "coder". If the act(s) of "management" require several separate skills, and growth requires identifying, leveling-up and field-testing these skills, the best orgs would find ways to divide management responsibilities among as many actors as possible.
I think we inherited an unhealthy idea of "management hierarchy" from military-inspired organizations, who value efficiency and top-down strategic control. Organizations built around creativity seem to have more success at sub-dividing and delegating managerial roles (assistant director, head of layout, editor-in-chief, etc.)
Nothing's perfect, but I'd love to see us adopt more of a mindset where we give people bite-sized responsibilities and, if it works out, we can train them to take on bigger responsibilities gradually.