You make the assumption that any computer we'd try to use to replicate it will inherently be digital and electronic. If we prove unable to replicate a brain this way, nothing is stopping us from using biochemical systems instead.

Analog computers exists, and we have used bio-mechanical systems for computation... Heck, the first "computers" were humans.

Getting hung up on the current preferred paradigm of computation as the only possible one is one of the biggest flaws of the article.