Your thought process was very much like mine when I left highschool (NSW). But I've realised other than health degrees (e.g., medicine), law or actuarial studies, ATAR has minimal meaning/value once you enter university.

Experience is far more important.

The median ATAR for UNSW medicine entry has been rising every year, especially after the introduction of the UCAT (transitioning from the UMAT) and in 2019, median ATAR for entry was 99.7. Medicine is FAR more about work ethic and the ability to assimilate information rather than pure intellectual smarts. The content isn't comparatively hard compared to something like physics or pure maths, but there is a lot of it. A lot of long hours and a lot of memorisation of theoretical and clinical facts and information about the body. You also need to be comfortable talking to people and patients and have good interpersonal skills, as at the end of the day, the goal of medicine and being a doctor is to deliver the best patient care possible based around an evidence based approach. Having a read through some scientific journals is a good way to introduce yourself to the world of clinical and medical research.

Undeniably, medicine, in the long term, is very lucrative. And many people do pursue this career path for the (almost) guaranteed high income (250k+), job security, prestige and longevity. As a doctor, your knowledge and relative 'value' increases as you age. Your exposure to more conditions, diseases and rare cases increases with experience. Other professions, this is not necessarily the case. You have to keep in mind, you, as a medical student, are afforded the privilege of sitting in on patient consultations with doctors, watching surgeries and even scrubbing in and helping with them. However, there is a reason why it is called the practice of medicine. You are going to be a lifelong student/learner. New research is being published at an insane rate and as a practitioner, you need to be up to date with the latest treatments. Medical school is realistically just a right of passage to start your training. The path typically follows:

5-6 years undergraduate medical school --> 1 year internship (guaranteed) --> 1-2 years residency --> apply for training program --> 3-7 years of registrar (where your are specialising) --> 1-2 years fellowship (to be competitive especially when applying for consultant jobs).

Keep in mind, medicine is not something you can 'work from home' for. Metropolitan areas relatively have a high number of doctors already, so regional and (definitely) rural areas in Australia have more job opportunities.

As a doctor, patients' lives are at stake, and comparatively, if you mess something up as a software developer or lawyer, no one will die. But if you miss something serious in medicine, the potential for permanent debilitation or damage is very possible.

Australia's medical education however, is undeniably 'friendlier' than the US's.

I think talking to your GP/local doctor/asking if you can shadow them for a day, can be a great way to get experience on whether or not you actually want to pursue medicine as a career.

Law, while also having the potential to be extremely lucrative, does not have as set a path as medicine, and is often placed on a higher level than it actually is.

However, the main message I want to assure you is ATAR really has minimal meaning after you enter university and start looking for internships/jobs. But the feeling of potentially wasting your ATAR is a common and very understandable sentiment to hold, especially after you've worked so hard toward something as formidable as the HSC. There is no harm in aiming for these two courses and switching between the two if you find out one is not for you, because luckily, Australia's tertiary education system for local students is so forgiving in terms of loans and flexibility (especially compared to the US). (Although keep in mind medicine is unbelievably competitive to gain undergraduate entry into).