I'm sharing from my own experiences, and direct observed experiences of others.
My children can hold conversations with people of various ages, and use a wide range of vocabulary. They are able to hold their attention. They are not stuck in front of a screen of any type, with all the determental effects that is known to have, which can be observed in most children today. They are not bullied, nor influenced by mainstream "culture" they do not they use passive aggressive language or behaviour. Nor are they exposed to inappropriate concepts or materials such as pornography, whilst still children.
Nor are they isolated from other children, or even other adults.
They are however isolated from cultural degradation, as we get to control the adults and children and broader elements of the culture that they interact with, and how to interpret it.
It works well for us, and our family.
It's a tried and true normal practice for all of human history.
School is the new thing. It's original stated purpose is know as it was written and discussed quite openly, initially.
After the post war era the desired result and purpose of education started to change and new cultural ideas were pushed to culturally change countries generationally. This was also written about and published.
It's something we've thought about and looked into and we've decided that its not for us.
Interesting that meny qualified teachers make the same choice, just like of the few who work in tech programming and social media who actually have children of their own have extremely stricted rules about zero mobile phone, pad, app tech being used and even viewed by their own children, all the while pushing it on others and their children.