Nature has created conscious beings. It would be a bit presumptuous to assume humans will be able to do so too
Consciousness is clearly a different kind of problem than flight, for one thing it is possible to tell if something is flying buy not possible to tell if it is conscious.
It would be very presumptuous to categorically rule out that humans will create conscious beings. We don’t know how to do it yet but if nature did it, why wouldn’t we?