First, he was a true narcissist. And couldn’t control it. He didn’t deliver on his promises because he couldn’t pay attention to them if someone on Hannity was talking about him. He couldn’t listen even to good advice unless someone was sucking him off hard enough.
Second, he had no idea how to address any of the criticisms he had made to find a solution. He governed largely as a standard Republican, even when it hurt him. His lowest ratings came the day his McConnell wet dream tax cut passed.
Third, he sucked as a manager. He picked the worst people for his team. Made working for him completely unappealing to the best people for the job. And dear god did he not always pick the worst legal minds in the business?
Nothing worse than incompetence really. Nowhere near as much of a racist as Joe Biden. Nor as much of a fascist.