My entire point is that having yourself is categorically different than having an outsider. This is one reason why even elite athletes have coaches. Many elite athletes will train too much, left to themselves - it's hard to avoid the feeling of "I have not done enough". We're more receptive to a different person, that we trust, when they say "You've done enough. More will harm. Rest."
In my case, I'm unsure if having my advisor present would have made a difference. At that point, my work was almost completely self-driven - but that's rather the point of grad school. You're supposed to get to the point that you're calling the shots; the "authority" status of your advisor is supposed to diminish over time. But I'm also not convinced that having an absent authority figure is any different than not having one be design; I don't see how I would have acted any different if for some reason I had officially no longer had an advisor.
In my case, I'm unsure if having my advisor present would have made a difference. At that point, my work was almost completely self-driven - but that's rather the point of grad school. You're supposed to get to the point that you're calling the shots; the "authority" status of your advisor is supposed to diminish over time. But I'm also not convinced that having an absent authority figure is any different than not having one be design; I don't see how I would have acted any different if for some reason I had officially no longer had an advisor.