Having done home, school, and mixed education for my kids, I have regrets, wishes that things could have been different or I'd done differently with all of them. There is not one of those options I'm 100% happy with how they've worked out. I hope I'm instilling the importance of on-going learning for them to continue their learning as adults.
I wish we had better options or able to afford or access more options, and that some of the options now had been around when my children were younger. I've learned these along the way that I wish younger me had known.
For home education specifically, I wish we had a system like there is in my birth state where home schoolers have a liaison with the school district who reviews a portfolio of work and can give recommendations and support. I'm very envious of those who've had that and while I know many home educators who are against this sort thing being done in the UK, I think something like that could be a great help both for home educators and for families who are facing long wait lists or otherwise can't access schools that they wish because what we have now is inadequate. This would take funding and support that's not really around though and I don't think much of the rhetoric and sharp divide in the thread would help us get there.
Some parents might not have any GCSEs which is a basic requirement to become a teacher, so if a parent doesn't have those and doesn't have even a basic understanding of literacy and numeracy how will be be able to ensure their children have the skills they need to thrive in education?
And some schools are severely inadequate with staffing issues, safeguarding issues and/or are well known for not ensuring children with additional educational needs can thrive there and or don't handle violence and weapons well. We can pick holes in any type of education or go on about horrors of when children are forced to try to develop and learn in these environments. Few kids really get much of a choice in education.
Rather than ask how can a parent with no GCSEs educate their child, I'd ask what options does a parent like that have and why out of those would that parent pick to take on that responsibility? There will be a range of answers, some possibly grim, but many of them will be about a lack of better options and trust.
I don't have any GCSEs because I immigrated at an older age. I know some don't think I should be allowed to home educate based on either or both of those points or because I have disabilities. I've been told that, even by trained professionals - had one go on about how home educating with my accent is the reason my child was being assessed for speech therapy. Even my uneducated young mum self knew how much shite that was.
I now sit on a school board and have worked with data for a local academy trust and the LA, including with information around kids who leave school to be home educated. There is no generalizations I can make on them in terms of ability but what I see is systems so under strain and cracking that some parents don't see schools as a place that helps their kids thrive, many with good reason. Most of those kids do return to school, usually a different school, and I think that's in part because of the work done to help rebuild trust and how the steps that lead to removal can lead to more options being made available even if they're still not ideal ones.