If you think you can't live on 300k with a family in the bay area, then you need a serious reality check.
On a $300k income, even with one earner, you can comfortably afford a $1m+ home (of which there are plenty of single family homes available in many parts of the bay area), and while yes the COL for things like groceries/eating out is higher than in Austin TX, it's not high enough to seriously claim that it's not liveable
Show me a 3-4 bedroom house for $1M, and I’ll tell you how many hours the commute would take.
I work on the Peninsula. 90% of 3+ bedroom houses currently on the market here cost over $1.75M. Those below that, in the bottom 10%, are what you’d expect to find in the bottom 10%. There are many great places to live where I wouldn’t be forced to choose between that or spending a couple hours a day in traffic. Less money and higher quality of life.