This is partly because in Australia, regular nurses can do virtually nothing on their own initiative.

A friend of mine was an ICU nurse in Canada before moving to Australia. It was a long and painful process to get qualified again, and when she did, she found out she had been demoted from being able to meaningfully improve patient care (eg the prescriptions and diagnoses you mention) to a robot carrying out orders.

I intentional refrained from ranting about the medical profession’s protectionism in Australia.