This is a tough question since what's best for the team and what's personally best for the manager's career may be in conflict, at least when it comes to the long-term. A manager who doesn't do any coding will over time get rusty and get further and further away from the current best practices, latest library/framework hotness etc. This can lead to awkward conversations of the type where the manager suggests "let's do/use X" where X was the best practice 5+ years ago and then it has to be diplomatically explained to him/her that's no longer the best practice. It can also be dispiriting to the manager if they got into software development because they enjoy coding, but now they have to deal with planning, people management etc., which they might be good at, but it may not bring them the same level of job satisfaction.