Hmm... I myself am not a fan of the theory that aliens are responsible for technological genius, if this is what you mean?
Rather, I assume that a device that was a simple design at the outset will inevitably undergo refinement and improvement over time and under the intense scrutiny of technicians. You can often see this in examples of people who deal with the technical-mathematical-physical construction of certain instruments and become very professional at it.
I would not underestimate the human achievement. Shepard also says in his book that it must have been the intelligence of the hunter-gatherer cultures themselves that triggered technical genius, because these people paired 360-degree attention with concentration and patience, and it was this combination that made technical progress possible in the first place. I would therefore disagree with you and say that it is precisely this that fits together.

What makes us doubt our own abilities is rather the degree of ever greater specialisation in all professions, which gradually made up the technical language and one discipline is no longer able to understand the other because of the high level of specialised knowledge. Since now, in the modern age, most people are no longer technicians and inventors, but only users, the ability of people in general to understand the natural sciences from the ground up has become unnecessary and thus a certain dumbing down has also occurred. I include myself here as well. My ability to understand mathematics, physics and mechanics can at best be described as below average to non-existent. However, I know people where this is quite different.

I consider the question of whether humans are or are not responsible for technology to be basically irrelevant, since it is speculative whether it was or was not like that.

The discrepancy in human groups resulting from high specialisation and applications plus their predominantly city based existence has removed the need for us to fend for ourselves. The current, very crazy, twisted and strange-seeming efforts to "save the world" are also, in my view, a psychological phenomenon, because due to the lack of danger from natural threats to humans (animal and plant life) leads to an overly focused narrowing down to looking at and fighting humans among themselves. They have no "enemies" to which they are inferior.

The city itself is the most effective protection against wild animals and plants, without any wall. One might think that this would automatically make people less fearful of moving through the world. But the opposite seems to have happened. The fear and disgust of wild animals and other organisms has increased as a result, which proves to me that everything we don't encounter habitually is classified as unwelcome, gross and disease-provoking. Only those animals that we have made human do we grant an existence in our homes, i.e. cats and dogs and some other small animals. But we have so alienated them from their wildness and turned them into pets that we think we are doing them a favour, whereas it is they who are doing us one by sacrificing themselves to live in captivity to please us.