I also feel like you're painting companies outside Silicon Valley with a pretty broad brush.

There's nothing about a healthy engineering culture that makes it unique to Silicon Valley, and there are many, many companies in those regions you mention that would take significant issue with that generalization.

If you want to optimize for annual salary, Silicon Valley is probably the place to be, but if you want to optimize for happiness (however a developer may define that for themselves), it's just one of many potential places to go, and if you want to optimize for work/life balance, it's probably not even in the top 10.