I live in Seattle, not San Francisco, but we have some similar issues with our schools. I'd really prefer to send my son to our local public schools, but if they aren't challenging him appropriately then my wife and I obviously aren't going to just give up on his education. We'll either pay for extracurricular enrichment like the person in this article, move to a wealthy suburb, or send him to a private school instead.

That's a much worse outcome from an equity lens, but there's only so much you can expect people to voluntarily sacrifice for the greater good. Asking higher income parents to risk their children's future is a lot.