> is the single worker even needed

Because he is? I do not expect for some sort of universal “AGI” to emerge within my lifetime which would supplant humans in every area (of course what do I know.. but still there is no real indication we are even remotely close to that currently)

> default is to attribute all the generated value to them when it really isn't the case

Certainly, you should attribute a significant proportion to the people who installed the automated system and even more to those who designed it.