I've been slowly reading Pete Walker's book Complex PTSD, and he has some interesting ideas about personality disorders and developmental trauma, so I don't want to start waving around the word "narcissism" as if Elon's behaviour can't be caused by ongoing environmental pressures, but there are significant indicators from employees, and even his first wife, that he's been like this for a long time.

He's just never been as exposed as he is right now, since his employees have bent over backwards to keep him away from making product decisions.

Elon's been sucking his own dick since before any of us ever heard of him. Really, the media's just been sitting around watching him do it.

incompetent and incapable

He was truly good at getting venture capital and at getting the ultra rich to hand him over cash. He was (and may still be) good at hiring skilled sycophants.

He's a horrible manager and an awful decision maker.

His true skill was applying unreal amounts of pressure to very skilled people to pull off momentous things and being very lucky that they didn't explode in his face.