I think this is a tough one. I HE'd my DS for what would have been his first year of school with an initial intention of continuing indefinitely. But I literally could not come close to meeting his need to be with other kids so he now attends a small independent forest school which we are insanely lucky to have access to.
A few years ago I would have railed against the idea that HE'd kids need to be checked up on. My DS was years ahead academically because we just unschooled as a way of life and he learned rapidly as his natural curiosity is voracious. I was nervous of the idea of inspection and even from when DS was a toddler, I had started keeping a folder on my desktop of photographs of anything "educational" that we did. When I put up posters, bought games or books I'd look at them and our house as an assessor would. I resented the idea that someone would have to come and examine me and my parenting and decide if I could continue as I saw fit with my own child, as if I wouldn't know what was best for him. It does feel like an intrusion and while I understood why it would happen, it still feels like an overstep.
However, in the time that I did spend home educating, I did see children who were being let down. People who described the most dynamic home educating lifestyles online who were, in reality, really not providing their children with as much as they truly needed. And don't get me wrong, school wouldn't necessarily have met their needs either but there was often quite the gap in the way their parents described their education at home compared to the reality. I saw an awful lot of home educating families who I ultimately felt had chosen HE as a way of isolating their kids from aspects of the world that they didn't like. None of this was enough to be a concern in terms of child protection but it was sad to me as I had seen HE as a way of opening up my child's world and tbh, it ended up just being closed off in a different way.
I also became aware of a handful of families where there is, imo, genuine concern. There is, not too far from where I live, a number of families who have relocated here from other countries because of the freedom to HE with minimal interference. They are religious fundamentalists and their children live an extremely sheltered life and are in all honesty deeply indoctrinated in a way that will severely hamper their ability to engage in the world around them, now and as adults in the future. It's very, very worrying and after meeting them, I think I'd happily submit to more regular HE check-ups or adhere to some sort of 'world curriculum' if it could possibly lead to children like that having a better chance of genuinely learning about the world.
I mean that for independent schools too. It's good to have the freedom to teach our children as they need but we should be aware that there are parents who warp that freedom to suit their own 'needs' rather than their children's. I don't want to benefit from a freedom that allows a child to be abused. There isn't an easy solution, I want my DS to keep on having the best type of schooling I can find for him, which just isn't any of the current state offerings. But ultimately I want to find a way for him to have that, while also ensuring that other children aren't slipping through the cracks.