How many parents can effectively teach calculus, statistics, Spanish, French, or German at the AP level? A whole lot of kids get a better education on the technical side because of good public schools.
When it comes to political bias, many teachers are terrible, and it’s the parent’s job to fix that if school teachers cross that line. But the good teachers (and there are many of them) do a better job that I could do in several areas - even parts of history, and I love history.
If you have shopped for homeschool curriculum you would know there are many choices for advanced study that do not require the parent to be an expert in order to facilitate the student’s learning. As one with a degree in Biology I know what is required with the more technical degrees and it’s not impossible to homeschool at the high school level. My dad is a retired Chemistry/Physics teacher and was skeptical until he saw what is available.
My high school age boys are friends with kids who go to public school. Whenever a conversation about school work comes up the public school kids are shocked at what my kids do. All have said that their school is so much easier. Our curriculum doesn’t have to aim for average as I am not teaching to the middle like school teachers have to. My husband is a teacher and would never send his children to school as the literature choices and conversations are greatly dumbed down from what is in our home. I know that I was not reading Henty or Ballantyne as a middle school student. I certainly wasn’t reading Jane Austin while in second grade as my daughter did. My literature class read Red Earth White Earth my junior year. It was eye opening to me and not due to the rich prose. I was exposed to ideas that I would not want to read about now, they were depressing and graphic.
Also, AP classes are high school teachers teaching classes that give college credit. One doesn’t need an AP class while homeschooling because you can just take the college class as a PSEO student, either at the local college or online.
If a parent doesn’t have the education required to teach high school level classes after graduating from high school, then our educational system is failing. Why would anyone place their child in it?