Yes, and ultimately this question, of what gets built, as opposed to what is knowable, is an economics question. The energy gradients available to a bird are qualitatively different than those available to industry, or individual humans. Of course they are!
There's no theoritical limit to how close an universal function approximator can get to a closed system definition of something. Bird's flight isn't magic, or unknowable, or non reproduceable. If it was, we'd have no sense of awe at learning about it, studying it. Imagine if human like behavior of intelligence was completely unknowable. How would we go about teaching things? Communicating at all? Sharing our experiences?
But in the end, it's not just the knowledge of a thing that matters. It's the whole economics of that thing embedded in its environment.
I guess I violently agree with the observation, but I also take care not to put humanity, or intelligence in a broad sense, in some special magical untouchable place, either. I feel it can be just as reductionist in the end to demand there is no solution than to say that any solution has its trade offs and costs.
For what it's worth then, I don't think we're in disagreement, so I just want to clarify a couple of things.
When I say open system economics, I mean from an ecological point of view, not just the pay dollars for product point of view. Strictly speaking, there is some theoritical price and a process, however gruesome, that could force a human into the embodiment of a bird. But from an ecosystems point of view, it begs the obvious question; why? Maybe there is an answer to why that would happen, but it's not a question of knowledge of a thing, or even the process of doing it, it's the economic question in the whole.
The same thing applies to human intelligence, however we plan to define it. Nature is already full of systems that have memory, that can abstract, reason, that can use tools, that are social, that are robust in the face of novel environments. We are unique but not due to any particular capability, we're unique because of the economics and our relationship with all the other things we depend upon. I think that's awesome!
I only made my comment to caution though, because yes, I do think that overall people still put humanity and our intelligence on a pedestal, and I think that plays to rationalist hands. I love being human and the human experience. I also love being alive, and part of nature, and the experience of the ecosystem as a whole. From that perspective, it would be hard for me to believe that any particulart part of human intelligence can't be reproduced with technology, because to me it's already abundant in nature. The question for me, and our ecosystem at large, is when it does occur,
what's the cost? What role, will it have? What regulations, does it warrant? What, other behaviors will it exhibit? And also, I'm ok not being in control of those answers. I can just live, in a certain degree of uncertainty.