That reads to me like it's demonstrated to be superior for employees who understand their work and how to do it, but training employees to that point is not occurring. I don't think this problem is inherent to the format - every place I have yet worked has de-facto replaced most or all of their training program with an on-the-job copying of tasks and routines from more experienced employees. That crutch has been removed and the absence of quality training programs is further highlighted. Understandably, this will vary wildly with field and firm, and developing an analogue to that type of informal information sharing is already occurring from what I've read.

Doubling down on what the other guy said, the answer is structured training instead of mashing people together hoping they learn by osmosis