Not entirely accurate. When they were shit, prior to 2007 roughly, when a Blackberry was still a business Sidekick, people were pointing out how ubiquitous and important they would be, and that lasted years longer. I think iPhone 4 is when that transition stopped, so at least 4 years of boosting.

Not to mention that bill gates himself declared that the internet wouldn‘t be quite useful but a stray fire and soon gone. Biggest misprediction ever