The powers LAs have are more than adequate. They can make informal enquiries into the educational provision being provided, and if they believe that provision not to be suitable or if they receive evidence to suggest that a suitable education is not being provided they can issue a notice to satifsy or ultimately a compulsory school attendance order. Their duty, just like social services, police etc. is a reactive one rather than a proactive one, home edders are presumed to be providing a suitable education unless there is reason to assume otherwise, which is as it should be. In this country we are innocent until proven guilty. Those suggesting that home edders should be proactively monitored will presumably also welcome regular social services monitoring of their own children and regular police searches of their home to check for evidence of crime; afterall, nothing to hide nothing to fear, right? Should school kids be monitored in the school hols when teachers aren't around to keep an eye on them?
It is senseless to compare school ofsted inspections with home ed. Home education is the default option for education in this country, and even though many (most) people choose to outsource this by sending their child to a school, parents are still ultimately responsible for their child's education regardless of where the child is educated. Even if your child goes to school, the responsibility for ensuring they receive a suitable education still lies with you, the parent. Ofsted inspections exist because the school is answerable to parents, it is providing a service and parents need to be aware of the quality of that service to ensure that by sending their child there the parent is fulfilling their duty to provide a suitable education. Parents who are fulfilling that duty themselves rather than outsourcing it don't have any use for an ofsted inspection.
In the handful of Serious Case Reviews where the children in question were home educated, they WERE known to local authorities, often to multiple different authorities for years before they came to harm. These children weren't failed because they were home educated, they were failed because the state failed in it's dury of care and didn't use the perfectly adequate powers it had to ensure their welfare. I don't know of a single case of a home educated child who came to harm and who was truly invisible to the authorities. Take the recent case of Dylan Seabridge who died of scurvy, in news reports he was claimed to be invisible due to home ed and yet if you look into the case, local authorities WERE aware of him but didn't act.
Home educated children aren't invisible. If anything they are more visible in the community than many school kids. My children are seen by neighbours, at the shop, the supermarket, parks, soft play, at their home ed groups (some taught by home ed parents but others by private tutors) at their mainstream classes. Lots of the people who see them on a regular basiss are professionals who are trained in safeguarding. A home ed child out and about during school hours sticks out like a sore thumb and on an average day we get stopped multiple times by nosy/interested people, we are anything but invisible! You could argue that home edders with something to hide may stay at home and not take their children out and about, but surely then they're conspicuous by their absence?! No children are truly invisible, all kids are registered at birth, a child who hadn't been seen by a doctor for ages would be a red flag in itself. I can't even put the bins out without my neighbours seeing me, let alone hide my kids. If anything it's an argument for more sense of community, for neighbours to look out for each other more and to report concerns if they have them. As I said, the evidence doesn't support this idea that home ed kids are invisible - in all the serious case reviews where home ed was a factor the children were known to authorities. The problem is often that different agencies don't communicate properly with each other and share information properly.
School isnt a garauntee of safeguarding either. Daniel Pelka anyone? Eating out of bins right in front of his teachers and still allowed to starve to death. I believe his mother convinced his teachers that he had an eating disorder and so his behaviour was left unreported. Often primary aged children are only taught by one or two teachers, it can be easy to pull the wool over one or two people's eyes, much harder to do that in a home ed community where the kids are seen by multiple different parents, tutors, group coordinators etc.
If anything, home educators are unfairly over scrutinised rather than not scrutinised closely enough. A recent study using FOI requests from LAs found that home educating families were considerably more likely to be referred to social services, yet it was significantly less likely to result in a child in need or child protection plan than for school families. Studies of outcomes for home educated kids find that they generally do well educationally and socially and many adults who were home edicated have now gone on to home ed their own kids. The evidence just doesn't support this idea that home edders are abusing, neglecting or failing their children, educationally or otherwise.