Or scales sub-linearly with hardware. When you're in the rising portion of an S-curve[1] you can't tell how much longer it will go on before plateauing.
A lot of this resembles post-war futurism that assumed we would all be flying around in spaceships and personal flying cars within a decade. Unfortunately the rapid pace of transportation innovation slowed due to physical and cost constraints and we've made little progress (beyond cost optimization) since.