It wasn't that Sears was unable to adapt to new realities, they merely had a incompetent hedge fund manager CEO who was unable to separate his fantasy world of Objectivist delusions from reality. He tried to implement a management structure based on Ayn Rand novels, with predictable results. Sears didn't die a natural death, it was the victim of yet another Objectivist murder.
https://www.inc.com/erik-sherman/sears-ceo-eddie-lampert-sho...
https://www.versobooks.com/blogs/news/4385-failing-to-plan-h...