Kay at PARC in the 70s went from having seen a sketchpad demo to having a complete functioning live-editable GUI with network transparency in 10 years, because of government ed-tech money.
The pointing devices we use, the look and feel of our UIs, and our UI metaphors haven't changed since the 70s except in terms of resolution. Our network protocols haven't much either.
Somebody who had used an Alto in 1979 could travel through time and sit down at a modern PC and know basically how to do most tasks -- they would think of a modern PC as a faster but less featureful stripped down Alto clone, like the Star was.
The best possible outcome, under the VC model, is that actual costs are low & the VCs get wild profits in the short term, after which they sell their stakes & don't need to care anymore.
The easiest & most reliable way to do that is ponzi
The difference in development between the first 40 years of CS and the second 40 is absolutely not the result of the low-hanging fruit all being picked. The most interesting technical work is being done by individuals and small groups still.