For example, if they only inspected framing at the end of the build they would have to remove the interior wall linings to check it had been done properly.
One of the reasons councils do this as the project progresses, rather than at the end, is so they can see work while it is still exposed. Through regular inspections, you and the council can be confident that the work has been done according to the consented plans. It could also prevent the council from signing off the build. It might mean some work has to be undone and redone. A missed inspection can have significant consequences for the owner and contractors.