The advantage with democracy is that it is slow and most of the time end up with fairly sensible results. Decisions are often so complex that it is impossible for one person to actually understand it all. A consortium of advisors could fill that role, but they have to be benevolent and trustworthy too. Their decisions have to be based on something, so the advisors need researchers and people gathering intelligence and statistics. Those people also have to be trustworthy.

All these layers have to be with as benevolent as possible. In a well functioning democracy, all layers would feel safe. It is really important to be safe from harm when giving bad news, or telling the dictator/advisors that their idea is really dumb, and would be a waste of resources or have a bad effect.

You could argue that a benevolent dictator would welcome bad news, other arguments. However the difference in power would certainly make it scary anyways.

Succession is another issue, and mental decline. Some people become quite mean in old age.

The closest thing I could envision might work is some sort of semi-democratic technocracy. I still think improving democracy is better though