The news reporters forty years ago introduced the cell phone as a world changer. And is so often the case, this heralding of a new age was decades early. Motorola’s first commercially available handset, the DynaTAC 8000x , took ten years to hit the market.
For the cell phone to become ubiquitous required some technical advancements, but no real breakthroughs. From the point of view of a mobile phone, it has been mostly evolution since 1983.
In fact putting computing performance aside for a moment, you could argue that the improvement has been flat since the transition from analog to digital signaling.
Adoption of mobile phones depended on the rollout of infrastructure which itself depended on the usual return on investment considerations.
Consider a few of today’s future tech promises: quantum computing, nanotechnology, and renewable energy. Ask not what these technologies will do for you or how they might change the world, but if and when they will be commercially viable.