It's plausible that in many settings this is actually most efficient from the point of view of the company. Do training on the things that can cause trouble lo

It's plausible that in many settings this is actually most efficient from the point of view of the company. Do training on the things that can cause trouble longer term (inconsistent tooling taking over, security issues, company-specific things you cannot find online) and just hope people pick up the rest as they go. Good workers will usually manage. The people deciding how to train new workers maybe don't even know what kinds of "main" knowledge a given worker would need. Rather than assigning an expensive senior worker to training them, they might hope someone good willing will do it in their spare time.