Thus there are rows and rows of 3-4 story buildings instead of high rises full of apartments.
No, when tech people talk about "building up", they're almost universally talking about replacing tenement buildings in the Mission with high rises. This has the unique property of displacing extremely poor people, and allowing tech people to live in luxury buildings in a small neighborhood that has recently become trendy, but was historically desirable only to poor people.
The problem isn't permitting or NIMBYs...it's that a relatively entitled population of recent arrivals have lost their fucking minds, and expect to be able to cram into the same 20 blocks of SF and not have to pay for the privilege. When they don't get what they want, they blame the laws for not allowing them to get what they want.
The "real" solution is for the city to "incentivize" tech companies to locate elsewhere, but given that our local politicians have fallen in love with this bubble, I don't see that happening.
Whenever a recruiter calls and I (accidentally) answer and they proposition me with a job in SF I tell them I would need to be paid twice as much as I'm earning now (in Seattle) to consider it. And I'm compensated well. It's true, and as a side benefit it usually ends the conversation quickly.