Thats literally how it works? All the apprentices are now journeyman, they go off on their own, and they hire a new batch for the next multi year project.
It’s not feasible to continue a company with thousands of workers making $50 plus, when you can get the same work done with $20 laborers and apprentices.
Same thing happens, apprentices are now journeyman and can work on their own, and new apprentices can do the same work for a third of the price.