Doctorate education in the US is a scaffold towards academic positions in colleges and universities both in and out of the US. The usual conversation is around the time it takes to get a degree (read more here) and what Academia and related jobs will morph into during the next 5 to 10 years (read more here).
The model of apprenticeship still holds. While the socioeconomic and technological conditions have changed dramatically over the years of industrialization and the Internet revolution, the apprenticeship model has not changed all that much. An apprenticeship aligns with the goals of the expert. The expert aligns with the goals of the employer. Thus, it is the employer (university) that is in the position to align goals of the expert (faculty) with goals of the apprentice (student).
In the US, doctoral degrees require more coursework than in most EU countries. Different disciplines operate under considerably different budgets. While university-wide services are the same, departmental services vary considerably. Computers aid us in our daily routines. Information retrieval is easy, but its validation is a problem. This is why learning by practice becomes more and more relevant to understanding phenomena rather than learning names. Higher education in the US is really linked to bank loans. Graduate education offers assistanships that enable people to acquire more education.
In short, education is the business; research is a goal; money is a resource; time is the currency. Here is a metaphor: a pipeline pours graduates into a pool. How well can graduates swim? Where graduates swim to? It seems the expectation is that doctorate education is a way to academic faculty. Nevertheless, the number of doctorate graduates is much higher than faculty positions. Currently, doctorate education is not just a way in academia and in the US, there is a high cost to it.