Yes, I've made this point many times. The beginning of a sigmoid looks like an exponential. Not only can we "never be fully certain that what we are observing isn't in fact following a logistic trend before the inflection point", we can always be fully certain that *every* *single* *exponential* *trend* eventually passes an inflection point and saturates into a sigmoid. Continuing an exponential trend beyond that inflection point requires a paradigm shift. No physical process can grow indefinitely. There are always friction terms in the dynamics equation that eventually become dominant (energy consumption, heat dissipation, quantum effects, thermal fluctuations, communication bandwidth, mass/energy density....). Even processes that *appear* exponential on a long time scale are actually a succession of sigmoids, in which each new sigmoid is caused by a paradigm shift. A good example is Moore's Law. It is saturating right now. But the exponential progress of the last 7 decades is due to a succession of technological paradigm shifts that weren't pre-ordained. Each paradigm behaved like a sigmoid. Each new sigmoid overtook the previous one. The envelope turned out to be exponential. We haven't seen similar paradigm shifts in, say, airplane speed or space travel. Technological paradigm shifts require scientific breakthroughs.