Earlier quoted context omitted.
Correction: You _have_ to specialize in the fields that you are good at; not what you want to be good at because you can't compete in the other fields. A couple of million years without advancing is hyperbole to the extreme; specialization which you are touting has only existed for 100-150 years or so (see Foucault, Frankfurt school etc...).
Specialization and division of labor is literally a defining aspect of civilization. Did you forget a couple zeros? The industrial revolution alone was starting around 1760, which is 260 years ago, and evidence for the existence of civilization extends quite a bit further back than that...
/Collaboration/ has been a hallmark of civilization; but it is revisionist to say that we have always specialized to this extreme or seen it as a necessary goal. For example, the blacksmith of feudal society didn’t only make spoons, nor the farmer a single crop. If we want to critique previous civilizations; we even need to be wary of the fact that such systems were determined primarily through morality, such as /Plato’s Republic/ or /Confucianism/ rather than any ideal of prosperity. The farmer was a farmer because that was his/her place not because they were better or worse at it.
Even if I’m being charitable and equate division-of-labour to specialization; which, I think is a /huge/ leap — it does not counter the original point which is there is little autonomy in what you choose to do for a living in the logical conclusion of a system where you must specialize to compete.