i love this framing! the skill that most distinguishes a novice/ineffective engineering manager from an experienced, effective engineering manager, IMO, is the ability to right-size your team's workload by saying no to the right things.
1. All engineering teams need some "slack time" (not the chatting app)
2. All engineering teams should be slightly understaffed and perennially non-empty list of things to do
The biggest Engineering Management learning is to reconcile these two truths of work.