Like you, my source is having been there and experienced it: my cousins, who were in private school, were quickly able to go back to in-person instruction; my sister, who was in public school, was not (until she switched).
Kids without the financial resources to do that just lost out.
Here's an NYT article from Nov 4, 2020, headline "In San Francisco, Closed Public Schools, Open Private Schools":
https://www.nytimes.com/2020/11/04/us/san-francisco-closed-p...
Here's an SFUSD memo six months later announcing the partial return of some kids to in-person learning:
https://www.sfusd.edu/covid-19-response-updates-and-resource...
Sure I'm dunking on SF city gov, because it deserves it! Its citizens are uniquely poorly served, especially its poorer citizens, in a city that is one of wealthiest on earth.
> During the pandemic, SF had in-person schooling at private schools, but not in public schools.
This is patently false. All of the private schools in SF that I’m aware of switched to remote learning from March 2020 to the end of that school year, and many had “hybrid” models (e.g. alternating one week in-person, one week remote) when they resumed in August / September.