Peep this visual:
Management does matter, and does develop people for roles and future roles, even though many managers don’t focus on the people side of the equation and spend all their time managing up, and even though many managers are hideously absentee, and even though calls for managerial training are often met with “Meh, a cost we don’t want to incur.”
The management of other people does matter. Recall this, fondly, as you move through your professional existence.