If it makes you feel any better he’ll be the one that gets slapped with malpractice if he fucks up. He’s inherently accepting a certain amount of liability as a doctor.
The other thing that comes to mind is he is trained specifically in his field to diagnose and treat. As a nurse you are trained to do what you do best.
That doesn’t give him a right to be on his phone all the time and be a dipshit. Eventually, that will have consequences of some sort. Currently he’s receiving less respect and earning a shitty reputation. That might come to bite him in the ass some day. Him being lax may come out in his work and bite him in the ass too at some point.
But I understand your frustration. I’ve got shitty managers who don’t know their ass from a hole in the ground and I constantly question how they got and are keeping their jobs.