It's actually pretty easy to understand. Affordability is not and never was the priority in San Francisco. What are the priorities are things like environmental issues, keeping the police in check (making it politically impossible to enforce any norms of civilized behavior, e.g. don't use drugs outdoors in plain sight), catering to every imaginable niche in society (the city has five legally-sanctioned languages and every ballot is printed in all five), having the best food, and providing some form of health insurance to even the lowest people on the income ladder.

A lot of this policy is admirable in its intent but has the (mostly) unintended side-effect of making everything horrendously expensive. How could it be anything else...new construction in San Francisco requires years of permit approvals, solar panels on the roof, there's pretty much a ban on any non-union labor in construction, etc.

All the employers know this, so they pay salaries that make it worthwhile for people to show up. So you end up with hordes of people making $200-300K paying $100K/year in taxes and $40-50K for a babysitter for your kids because your parents or other family live halfway across the country and nobody can afford to live here on $20-30K when single rooms in a 4br place cost north of $1K/month after tax. Oh, and the schools, roads, and other infrastructure are pretty bad, too, and there's trash everywhere.

The real suckers seem to be the companies willing to pay the wages to keep this whole huge ponzi scheme going. The whole thing is a massive transfer from shareholders to local land owners, and government employees.

I'm not being cynical, this is just how it works, after living here for seven years. The city has 800K people and an operating budget of $8 billion. That's $10K/head and it's still potholes and unfunded pensions.