No, I didn't realize I was talking with a schoolteacher. :-)
Sure, it depends on the kid. Each student has a different experience. Some students will graduate with honors, while others get lost in the mayhem.
Even in the better schools, social factors come into play. Social factors can affect grades dramatically. Outside of school, social factors are not an impediment to learning. And, if education were sold on the private market, we would have a greater choice between schools. If one school isn't right for your child, you can try another.
While I'm all for the Free Market...you need to mention the natural addendum to this staement: IF one can afford the fees. Because my students are wearing clothes the moms have resewn and re-cut from fabric purchased in surplus stores. I couldn't figure out WHY the girls were wearing cammies or at least US G.I. camo patterns on some really nice looking dresses. A lot of kids join JROTC for the uniforms to wear! You can buy a surplus uniform for about $2.00 in some places. If mom or sister is an accomplished seamstress then nothing is impossible. Such is reality in the inner city. Especially in the little Haiti area of Miami-Dade County.
Without public schools, some kids wouldn't get any education. Some of those kids would be turned away by every private institution.