There is one thing that all widely read futurists have in common: they are wrong, most often spectacularly so. The first is inherent in the limitations of predicting. The second is inherent in the approach futurists seem to universally take.
Perfect prediction requires perfect models, which in turn require complete information. But information is infinite (c.f. irrational numbers) and can only be approximated (c.f. uncertainty principle.)
Accuracy is the measure of a prediction’s success. The closer the prediction matches the observed behavior, the higher the accuracy. The smaller the number of interactions in the behavior being predicted, the less information is necessary to predict the behavior. Applying quantum physics, for example, often entails predicting a single interaction of two particles and can be breathtakingly accurate. Weather, on the other hand, consists of myriad interactions of trillions of objects. Predicting weather can be breathtakingly inaccurate.
Futurists are spectacularly wrong because they consistently predict exponential trends in technology growth when that growth is never exponential. They are wrong because they predict continuous growth when growth will have interruptions. They are wrong because they emphasis the wrong trends. They are wrong because they do not account for side effects.
Study the history of any specific technology. It will start with a discovery or invention that enables it. At first a few will experiment with the invention and growth will be slow. Next a point will be reached where widespread interest in the novel technology develops and growth will accelerate in what appears to be an exponential fashion. It is this part of the growth curve that futurists base their prediction on.
But as more is accomplished, room for improvement retracts and improvement becomes more expensive to accomplish. Eventually the cost of improving the technology exceeds the benefit achieved by the improvement and growth slows to a trickle. It is this leveling off that futurists do not incorporate in their models.
Growth is interrupted by catastrophe. Malthusian population explosions pause for pandemics and the massive death toll of wars. Growth is interrupted by alternate technology that solves the same problem less expensively. Diesel replaces steam. Transistors replace vacuum tubes.
The Google search engine provides a clear example of side effects. Larry Page made two conjectures: that the best order to present search results was to rank them according to their usefulness; that utility could be correlated by the number of existing links to each result. This resulted in a very successful search engine. Result owners wished to have their results presented earlier in the list. They found ways to increase the number of links. This lead to search engine optimization (SEO) which amounts to an arms race between Google, extending the ranking algorithm to account for existing SEO, and page owners, changing their strategy to account for changes in the ranking algorithm.
Futurists find themselves in a trap. Dramatic predictions lead to widespread readership. Dramatic predictions easily result from exponential extrapolation of trends.The only cost of being wrong is embarrassment. Embarrassment is avoided by predicting far enough into the future that you will not be remembered as making them when they fail to materialize. Do you know who predicted flying cars in 2000, earlier in the 20th century? Neither do I, nor did I in 2000, when they failed to materialize.
I have not described all of the causes of the spectacular failure futurists, nor have I described their successes.