All human technology can be built using only rocks and sticks. Yes, even that multi-core CPU made with 7nm lithography process in your computer. In fact, it has all been built that way. Our ancestors made better rocks and sticks using the ones that they found on other ones that they found. Then, using those, made even better tools and so on. All human technology has been built with a tool chain that begins with rocks and sticks found in the pre-human natural environment. I really hope that historians will document the most important of these tool chains in detail.
The most productive tools from a backward-looking perspective are the ones with which the things that have already been built by any tool can be built with the least effort. This is the usual perspective that we have when picking tools. The economic effect is the value of what we build in excess of the resources that we use.
The most productive tools from a forward-looking perspective are the ones with which one can build more advanced tools, as the economic effect from their use is not bounded. When comparing such tools, the one with which the more advanced tool gets created with less effort is the more productive as the exponential growth of productivity will have a greater base. Because of the exponential nature of the process, those who focus on the productivity of their better-tool-making-tools will eventually overtake those, who do not maintain that focus, even if the focused ones start off with inferior tools.
While it may seem that no conscious effort is needed for that to happen, as the fastest advancing technology will always become dominant anyway, it is not true. Without reflection on development, it is possible to get stuck in an inadequate equilibrium, whereby the tools that we happen to use are so vastly more productive from a backward-looking perspective than the best available forward-looking tools that nobody picks them up. Of course, the more people there are, the less likely it is, but it does happen from time to time. This is why it took our ancestors hundreds of thousands of years to develop past lower Paleolithic technology, even though they were just as smart as we are, or maybe even smarter. But they were few and the obviously best tools looking backwards were not the best tools looking forward. And then someone somewhere figures out a way to make a better tool using the worse tool. Without reflection on development, it only happens by accident.
It can even get worse. Division of labor increases productivity enormously, but excessive dependence on it can make such lucky accidents less likely as everything with meaningful backwards-looking productivity requires the cooperation of too many people who all need to be convinced to do something in the not obviously best known way to do it. This situation is fraught with the risk of serious rollbacks, as a disruption in the division of labor due to any number of reasons including the loss of population numbers or key people might result in not even being able to maintain the already achieved levels of technical sophistication, as the best tools available for use are (often far) beyond the capability of anyone to make. This can cause a cascade of abandoning already mastered technology until the reproduction of what is available becomes again within the means.
Thus, developers of forward-looking technologies must strive for simplicity to reduce the required number of people but also to make it accessible to the largest possible number of people. It should be simple to use, but also simple to reproduce and simple enough to understand in detail by small groups of people. If we care about the ease of use of a tool for making more advanced tools, everything else being equal, the simpler tool is clearly better.