Of course you can learn things without this structure, but having a phd is a reasonable short hand for ability in independent innovation, perhaps companies lean on it a bit much, but that is not unique to phds.
The main problem I've had bridging phd's to commercial work is hitting the right focus on skill development in areas that were deficient/missing in their course of study. A classic example, a lot of technical phds who have programmed every day for many years ... are not skilled programmers. They can become so, but have to want to learn (and not dismiss it as "trivial")