https://www.sfgate.com/realestate/article/San-Francisco-home...
https://www.sfchronicle.com/bayarea/article/Rich-residents-w...
Businesses are what pay it. Hence the payroll tax a few years ago. Hence the relative ease of getting new office space approved vs. new housing.
To preserve the tax base, the city govt. will need to keep business around and office space full. Even if the crotchety old money people who pay pennies per year for their semi-private streets don’t like it.
Hold on a sec -- the parent was asserting that wealthy people still want to pay big bucks to live in SF, even despite the huge tax bill. They gave an example of an expensive recent property sale, which would force a huge property-value-up-assessment and thus a big tax bill.
You're then citing a story to refute this belief, which talks about a very unusual case where a tax-nonpayment-sale was reversed, treating like it never happened (because corruption), and thus avoiding the up-assessment. That's not responsive to what the parent was talking about.
Now, you're right that wealthy, very-long-time SF residents do avoid most of the property tax due to never having sold and the Prop 13 shield. But that isn't relevant to a case of a new buyer picking up a property like that commenter was referring to.
Those realtors just did what they all do in SF - underprice a listing by 30%, then when it selling at what they thought it would, hype up their "realtor expertise". These two got free publicity out of it.