Since the original point of this chain was a comparison between the energy efficiency of biological vs machine learning, then we need to be trying to understand if the machine is more efficient than the human. You don't need to make some moral or philosophical argument about existential justification to accept that taking a more efficient approach is better, in that it generally enables more life for the same energy.

If the true, total cost of a machine to perform some task is less than a person to do the same task, then the machine should do it and the person should move to do what the machine cannot. This means more energy is available for everything else, living included.