Humans have taken tools and industry to a whole new level, but there's nothing unnatural about that; it doesn't make us an "abnormal" species, whatever that means. But this is something well beyond just "the next step." We're directly and consciously changing our own genetic code. This is also not unnatural, but it represents an existential threat.

> Who knows where it'll go, but homo sapiens isn't equipped to be space-faring or even survive on this planet beyond a few billion years.

So? I don't see how that's an argument for human genetic engineering. If we want to perpetuate life throughout the universe for some reason, we can send probes loaded with microbes, maybe even advanced probes that can incubate more advanced animal and plant species to create an ecosystem. In your scenario, humanity is presented with its extinction through either natural causes or by being the architect of its own destruction. I'd prefer the former.