Why can't a narcissist keep a job?

It depends in the nature of their job. My npd mother was a supervisor over a factory floor of over a 100 women & men. She worked there 40+ years. She wouldn't miss a day of working in the environment of having power & ordering, her workforce about, demanding, power crazy woman. Her job gave her great control & power over her workforce, she could hire & fire you & woe betide anyone who didn't bow down to her. She loved the Narcissistic control she had & she used it.

Because they're caught up in all the lies and acting and faking it in funny s*** that they're up to it's it's very confusing Plus the majority of them are drug and alcohol drug addicts and alcoholics and it's just hard for them to be consistent with the job you know