In what is otherwise a great article, this stands out as having rather inadequate reasoning to support your point.

Unionizing is a classic response to the asymmetric power between employers and employees. However, "unionized worker" is not an identity in the "identity politics" sense.

That power concedes nothing without a demand, and that one person as-a-sole-person has too quiet a demand to be heard, can both be granted without identity politics being the outcome.

So can you fill in the missing steps?

To me it seems like identity politics exploits the psychology of tribalism far more than the unease of the forced choice naturally leads to it. But perhaps you see it differently?