[lisa_henderson]

This article misses what seems like the most obvious explanation, which is that the USA economy has recovered from the Great Recession. We had a stretch from 2009 to 2014 when it was difficult to find any normal investment that paid better than 1% or 2% a year. Seeking yield, money poured into startups, because they seemed like the only thing that might be able to offer better than 20% returns (assuming a basket of startups, most of which fail and some of which return 100x).

Since 2015, the economy has returned to almost normal, so the need to invest in software startups is reduced. And this would most likely effect San Francisco the most, since it had received the most investment during the era 2009-2014.

Now that the economy is almost back to normal, there are a lot of areas in the economy that offer possible returns. The need to focus on software startups is diminished.