Omniscience.

The wise person considers a decision with the sober acceptance they may be wrong.

This possibility focusses their mind, motivates them to consult widely and weigh up all the evidence. Even to rehearse the eulogy for their failed endeavour in their head.

The person exercising positional power has no need for that nonsense.

Consulting others is a waste of the authority given to them that commissions them to be decisive. It also undermines the reverence others have for their omniscience.

Besides, if anyone else could do a better job, they’d have the job.

All the positional power person rehearses is pointing the finger of blame.