It's worth noting that we hit the wall only with respect to silicon-based transistor-packing wafer technology. There are other alternatives (ex. SiGe instead of just Si, memristors, photon instead of electron circuits, etc.) that could allow significant increases in compute capacity. They just haven't been explored or invested in to a large extent because it's been relatively cheap with proven ROI to follow traditional manufacturing paths to their maximum. Other technologies like Li-ion batteries are in the same boat - there are big advancements yet to be made in the broader space in general, but the specific processes, chemistries, etc. being used today are nearing their physical limits.

I'm personally still hopeful for a sci-fi future, just based on a series of ramps and plateaus as we progress through the limits of each specific technology.