@raganwald I liked Ton Roosendaal's attempt at framing this (meaning the nurturing of juniors) in his 2024 keynote as "the volcano model": you make sure talent rises to the top, and in order to prevent the top from getting crowded you help (some of) them find jobs elsewhere https://www.youtube.com/watch?v=VZ5022VaMmA&t=745
(What's even more clever about it in Blender's ca;e is that with this approach Blender becomes a cultural export to other companies)