Because the very thing that earned them the promotion is often the thing they now have to stop doing.
I see this all the time.
Almost every leader I work with is somewhere on the same arc.
It starts with competence.
Getting good at the work itself.
Then comes a harder shift.
Leading the people who do the work.
This is where your old strengths can quietly turn into liabilities.
And then, if you keep climbing, a third shift.
Leading other leaders.
Here almost nothing is yours to do directly.
And everything depends on the conditions you set.
Here's the thing:
Each stage asks you to let go of what made the last one work.
Which is why growing as a leader is mostly subtraction.
The hard part isn't deciding what to take on.
It's figuring out what to put down.