Homeschoolers tend to outperform their regular school peers. But I think parental involvement is a significant differential and is probably contributing to the outcomes.
"In study after study, the homeschooled have scored, on average, at the 65th to 80th percentile on standardized academic achievement tests in the United States and Canada, compared to the public school average of the 50th percentile."[1]
"Descriptive analysis reveals homeschool students possess higher ACT scores, grade point averages (GPAs) and graduation rates when compared to traditionally-educated students."[2]
That doesn’t control for socioeconomic background.
Yes, homeschooled kids do better than the average. The average is also dragged down by the country deciding that if your parents are poor you should starve.