Bubble in this context means a unique environment that is unlike places on the outside of said bubble. It's not referring to a bubble like in the sense of a inflating market bubble.

The desire to work and have children is going nowhere. Like Hollywood, the careers are going to go away. The money that lubricates the Bay Area is all from the Middle East now, and the return on in-region labor dollars is declining.

I’m sure the return on in region labor dollars decline that you note is real but is it regional? Where in the US is the return on labor dollars not declining? Housing costs, including taxes, seems to be the big problem in the Bay Area. Workers are still productive, but they require higher pay to offset the demand for housing caused by all the foreign “lubrication” and tech-49ers.

For movies, it’s cheaper to lots of work in Atlanta

The US is already a bubble. Government is currently trying to make it burst as fast as possible. Getting back to the point where what women want doesn't matter again. HCOL will be a luxury term, life in debtors prisons will be the new norm.

Bubble: used to refer to a situation (esp. good or fortunate) that is isolated from reality or unlikely to last.