In USA part 141 flight schools typically promote flight instructors from graduates of previous courses. That may result in an organization in which only the minimum experience required to pass a flight test is passed on to the next round of students. Fortunately, in USA, independent intructors who may have many thousands of hours of varied flight experience are allowed to give instruction and recommendations for flight tests, conduct flight reviews without or wthout training, and to provide any other flight instruction that those inexperienced instructors at a part 141 school can provide.
So far, no one has posted the Australian regulations/laws that define the instruction an instructor not tied to a part 141 school can provide.
Don't misunderstand me. Part 141 flight schools may be very good a taking students to the standard required to pass a check ride. Maybe that's all some students want on the path to their airline job.