Again the misconception created by stating it this way, is that natural selection is somehow capable of guiding the significant beneficial changes themselves, of somehow helping overcome the odds against such a remarkable fluke
But the significantly beneficial changes must all happen before they can be naturally selected as such- by pure chance as evolutionists would have it.
Natural selection goes without saying, it's the process by which the Mustang outlived the Pinto, obviously if you have a significantly superior design, it will outperform it's competitors- nobody debates this
Creating the superior designs by sheer fluke is the tricky part, make any random change in a 747, and the chances of screwing it up entirely, is always vastly higher than the odds of accidentally creating a significantly improved aircraft, this tendency increases the more highly evolved the design.
By these simple laws, nature selects the fittest yes- aka the least unfit, the least damaged version of it's predecessor. That random changes would somehow inherently favor increasingly superior designs for nature to select from is a fallacy.