Also, "optimizing"?
Do you think a bird uses its wings any differently than an airplane's to fly?
Also while we are on the subject, is there a general intelligence AI you would like to introduce me to?
The gap is certainly closing, but it's nowhere near where it needs to be to replace the need for humans. Maybe we'll get there soon, but it won't happen without some new approaches IMO.
Then again, I'm no longer active in the research aspect of the field, so it's hard to gauge how close we might be.
Unsupervised ML is different. From what I can tell (I work in ML and have extensive biology experience), human brains use a combination of approaches that combine unsupervised and supervised learning and oneshot learning and it's not clear that a true "learning AI" requires more technology than what we have today. I think that's an open question in the field but nobody is really addressing it head-on.