You’re basically right. Back when unions were a thing, they dubbed this behavior “working your wage” I.e. not volunteering for unpaid labor. “Quiet quitting” is a neologism designed by a think tank to shift the burden of responsibility to the employee

It’s a phrase meant to replace the old phrase “working your wage”, because that way of viewing it makes the whole situation less dramatic and more noble … and generates less clicks. Classic newsspeak.