> The moral of the story is that, even though all exponentials eventually become sigmoids, this doesn’t necessarily happen at the exact moment you’re doing your analysis. Sometimes they stay exponential for much longer than that!

All exponentials eventually become sigmoids? Don’t think this can be true without qualifiers.

All models are wrong, of course, but this is kind of "common sense" so it's not hard to accept as true in a natural system. How can something continue on exponential growth forever without reaching a new blocker that causes slowdown or encountering pushback that makes it an oscillator. A pendulum looks exponential when it is at its peak and accelerating down.

The issue is that the exponential-looking part of the sigmoid might contain all of human history, sure, but most folks who espouse this theory probably agree that over time everything reaches a steady-enough state to be considered non-exponential, or become oscillatory.