My ex was raised in the FLDS. They were taught to perform fellatio on bananas in school. Notice I didn't say homeschool because they set up their own private schools. Even so - she could read. Despite this, public schools have well-documented results by the score:

https://www.nuroretention.com/blog/officials-80-percent-of-r...

https://www.npr.org/templates/story/story.php?storyId=121374...

https://foxbaltimore.com/news/project-baltimore/baltimore-ci...

https://www.washingtonpost.com/local/i-couldnt-even-read-the...

https://phdessay.com/can-illiterate-students-graduate-from-h...

https://www.washingtonpost.com/news/answer-sheet/wp/2016/11/...

https://www.highschoolcube.com/the-high-rate-of-functional-i...

And the list goes on. Several of these articles cite a rate of about 20% of adults in the US being functionally illiterate, with about one third unable to read above a 5th-grade level.

If homeschooling produces better results than that, then I'm all for it. Again: Kids need individual attention which they can get more readily in a homeschool environment. In large institutional public education systems, they just get "passed along" as they may be one of 30+ students in a class, and one of 5+ classes a teacher has. Public school teachers don't have enough time in a week to spend one-on-one time with each of their students. In the 90s my high school had class sizes of 35+ and I'm sure it's worse now in some schools.