As a dyed in the wool market believer I understand the facts of supply, demand and filling a need. I think that is the argument you are making - the military and NASA supplied the need,demand and money for incentives. As a result, lots of technological progress was made.
There is an interesting book titled Connections by an Englishman named James Burke. It traces the advances of technology (science) from ancient Egypt into modern times. It shows how one thing led to another and when man was in a certain mode he kept refining and improving on the present technology.
Then all of a sudden, often in a non-linear way, technology would head off in a completely different direction and start refining something else.
Years ago the people at MIT were researching artificial intelligence, making computers more like people. They knew that if they were going to make computers like people they needed to know more about how people think. After lots of research by many people they decided that we learned by association. Often, “new” ideas were simply new associations of old ideas.
Naturally that is an oversimplification on my part as there are many, many nuances and details involved in that description.
From that background and much more I think that we would have done the same today. We would have kept refining the extant technology until we had nearly perfected it and then we would have headed off elsewhere.
I use as examples of the evolution of computer languages with each generation compiling more and more code behind fewer and fewer symbols. This allowed more software to be executed in smaller spaces. Along side that the evolution of computer storage and processing power made even more advances possible.
The invention of the transistor by Texas Instruments and other signal processing technology led to smaller and smaller circuit boards which in turn led to smaller finished products.
The USA is the leading country for venture capital and investment in technology. (or at least it was) The money is available for these advancements and private industry is much more efficient than government bureaucracy. In fact, nearly everything developed for the DoD and NASA are done by independent contractors. Yet, they too, are stymied by government rules and bureaucracy.
That is why I think we would have gotten where we are without the government.