I think the leadership component is very relevant here. A project manager / leader needs to be able to a) identify developers who could be 10x developers, b) develop their characters (some developers may be lazy or undisciplined or have anxieties that hold them back, so this needs to be solved first), c) recognize good technical skills and realistic self-evaluation (a developer that always wants a rewrite because he's certain that he will do it better than everyone before him vs. someone who tries to find a more reasonable way that may involve a rewrite).

Overall, this is a very difficult task. If you let developers that have undeveloped characters manage themselves, they'll create a huge mess. And personal development is generally a very difficult task and not something that a leader can control for most parts.