is the playing field really equal when it comes to achieving a decent ATAR in Year 12?
Yes it is actually.
Sure, statistically private schools/those living in Toorak get better results as a group than the others.
However, this is not because year 12 is any easier in those schools but because the majority of the people there tend to be more motivated/driven to succeed.
I did VCE at a
public school in the
outer suburbs
I scored within the top third of the state and we had a large number of students get ATARs in the 80s and 90s.
The subjects are exactly the same, taught the same way, use the same textbooks, sit the same exam and assesed using the same criteria by the same assesors regardless of your school, location, income or parents love life.
My point is it's up to the student to put in the effort if they want to receive high results, and there's no genuine cop-out for not doing so.