Why the particularly unsubtle strawman? Nobody in this thread has made a claim that remotely resembles "consciousness does not exist" or "consciousness is a byproduct of any sufficiently complicated system". Those are both totally different from "consciousness is, or results from, a biochemical process".

I think the argument you're making is much more reasonably applied in the opposite direction. The fact that we don't know exactly how consciousness works is no reason to jump to conclusions like "oh, it must be quantum-mechanical and/or incomputable", just like the fact that we don't know exactly how life evolved is no reason to say "oh, God did it."