I don't think I entirely disagree with you. I was generalizing the real phenomenon that we are unable to engineer competing mechanisms to those found in the wild.

That said, "region of worse efficiency" tends to happen all the time. The accurate argument would be a "region of untenable inefficiency". A legless bird that evolved the ability to fly its entire life from hatching to death is an unlikely evolution. Not coincidentally, finding ways to keep something up in the air longer-term than birds do is something our engineering is capable of.