The population is not "reaching equilibrium", it's shrinking. If it was reaching equilibrium you'd expect the births per women to be slowly reducing until it approaches 2.1 and then staying there. It's dropping substantially below that. And there doesn't seem to be any evidence that the contraction is temporary, the causal factors seem largely unrelated to the existing population size.
That's... not how equilibrium works. A self-balancing segway or robot doesn't reach the balance point and then freeze in place. There are oscillations. And it isn't a pretty sine wave either. Considering the massive number of factors that go into something like "global population growth", expect a VERY chaotic graph indeed, like the stock market, but worse.
How can you say it’s not temporary if it’s just started?