I have two frum families homeschooling on my block. To say “most families can’t do it” IMHO is a cop out.
It’s not a cop-out. It’s true. Saying it’s a cop-out is to claim that most parents could really be good teachers, but they nevertheless chose a different career, which is occasionally, but not usually the case, and to say otherwise, besides being IMHO untrue, is an insult to our rebbeim, moros, and teachers.
And those choosing to homeschool, in many communities, are not doing anyone a favor; their limited tuition is still something that the schools could have benefited from.
And the numbers given by SJS and zahavasdad, IME, are overinflated; most parents, in the schools I’m familiar with, are not paying nearly that much in tuition (either they are paying less than full, or tuition is not that much to begin with).