@ProPublica 25 years ago I was doing psychotherapy with low-income kids and families. I grew up in the West, in LDS-intensive circles. Every homeschooled kid I knew was pretty smart, fairly well educated (sometimes very well)--with occasional gaps in knowledge, like for evolutionary theory, for example--and slightly weird but usually not unpleasantly so.
In psychotherapy (which was mostly cognitive and educational testing once the clinic found out how cheap grad students are) I met half a dozen to a dozen kids whose parents had pulled them from public school. Almost every one of them was approximately as many years delayed in their academic progress as they had been out of public school. In other words, their homeschooling amounted to no school.
I was shocked at first, then realized I was seeing another side of this, condensed through selection bias (kids came to the clinic because of behavior problems or because the state was getting involved in the homeschool situation).
I suppose this was one of many things that shifted my inherited libertarian-conservative attitudes about government regulations.