To be a great leader, you do not need to be able to do everything or even know everything. But you do need to know enough about yourself to recognize your strengths, admit your weaknesses, and both understand and acknowledge what you do not know.
If you are capable of that you can assemble a team that compensates for your weaknesses and compliments your strengths.
Unfortunately if you are not capable of that, such a team won’t put up with your inability to lead competently; good people will quit, while the best will never accept the job with you. Then the only people you’ll be left with, that are willing to work for you, are a team of people who either can’t get other work elsewhere or are willing to be sycophants feeding your ego enough to convince you that you’re a good leader while everything around you falls to pieces.
The Republican president is not a good leader, because he thinks he knows more than everyone else, he thinks he can do every job better than every one else. And as this synopsis of a single day of his presidency shows, he is completely and utterly wrong about both of those things. He is also incapable of admitting a mistake, and more importantly incapable of learning from it.
He has already assembled his team of incompetent sycophants, and we’re all watching everything around him fall to pieces. The only one that doesn’t see it — including his supporters — is he, himself. His narcissistic delusions of grandeur shield him from any version of truth and reality.