I totally understand your point, as my cousins are perfect examples of negligent parents who “homeschooled” their children, but really did nothing. They were in that minority who were incompetent. Yet, my aunt and uncle did have the education to teach them, it’s just that my aunt, who provided the schooling, was a total, lazy bum who sat on her butt all day and didn’t do anything to help her children. They suffered for it and that wasn’t right.
Of course, public school teachers need to be held accountable for their ability to teach. And parents who wish to homeschool should be held accountable as well. I have no doubt in my mind that many homeschooled children probably do much better than their public school counterparts because they receive one-on-one education - much like what you’d get in private schools with very small class sizes. (example, my class in the private girls school I attended for a little while had only about 10 students. It was wonderful. I loved it) These situations are ideal - especially if you can also provide languages, arts, and other things. And in these situations, I think homeschooling is wonderful.
If my husband and I determine to homeschool our child(ren), I’m confident we will do a good job with them as we are both well-educated with my strong points in reading, literature, languages and my husband in math and sciences and both of us in music, but I would have no qualms with being tested for our competency either.