I'm reminded of the monologue from Terminator 2:

> Watching John with the machine, it was suddenly so clear. The Terminator would never stop, it would never leave him... it would always be there. And it would never hurt him, never shout at him or get drunk and hit him, or say it couldn't spend time with him because it was too busy. And it would die to protect him. Of all the would-be fathers who came and went over the years, this thing, this machine, was the only one who measured up. In an insane world, it was the sanest choice.

The AI doctor will always have enough time for you, and always be at the top of their game with you. It becomes useful when it works better than an overworked midlevel, not when it competes with the best doctor on their best day. If we're not there already, we're darn close.