I would say that it is bad when it has large derivative (positive or negative). However, the problem is not about >number of human beings< but about making agency that existing people have obsolete.
We're making slave morality obsolete. The sense of self dependent entirely on external performance. Reality is making it so that we will have very little value in that domain very soon. Because everything we do now will be done better faster cheaper by the machines.
That's going to be a pretty rough transition. I think the economic aspects will be pretty straightforward by comparison to the psychological upheaval!
