You are talking about Australia. I am talking about England, not Scotland, nor N Ireland, nor Wales. I apologise if that was unclear.
You live in a country which is a continent, with wide open spaces. I do not. To that extent, you have no
locus on England's education system, which was never designed to work in Australia, I can see perfectly well why a home education forms a part of your country';s education syllabus in the Outback. England has no Outback. You make no mention of checks and balances, other than to weigh them off as 'a can of worms'. From my point of view, that is obfuscation. You make the case for children who have apparently received a good home education: my interest is in what happens to those who do not. I write that as one social engineer to another.
Here is a
link to home education in England, when it goes wrong. It is out of date by 2 years and therefore may be stale. I doubt it, but am happy to be corrected.
Essentially, what the link demonstrates is that a lot of home education results from exclusions, bullying, or mental health problems for a child.
For me, the bullying aspect can be remedied by a switch in schools.
Exclusions are sometimes education-made: these may result in part from the English system with its league tables for schools and OFSTED reports. where schools may seek to exclude pupils who disrupt the overall results, and where other schools are reluctant to accept the banished.
Other exclusions will result from antisocial behavior, which is far more problematic, and more likely to lead to other schools refusing to assist, bcs of the league tables etc Back in the day, when Local Education Authorities had real power, they could move pupils around and insist on inclusion. They could also set up units for pupils who were outside the mainstream, for whatever reason. e.g. what we would now class as behavioural or mental health issues. And there were Special Schools, which dealt with pupils who had severe issues. e.g. home abuse These mostly no longer exist.
Back to Home Education in England: what concerns me is those instances where parents cannot afford tutors, and where the state does not intervene bcs the child has not been excluded.