Here's more data. This comes from the most recent graduating class of college students, so there's nothing more up-to-date than this.

I don't know about other fields, but those with physics PHDs frequently end up in finance or industry, where their skills in modelling, statistics and programming are highly valuable. Specifically, 3/4 of those working in the private sector made more than $100,000.

The first and third links you posted above deal with careers in academia, or academia + private research. The second is a blog about getting a university position. These jobs, like the lab positions you mentioned, are notoriously competitive. But the prospects for people who get jobs outside of academia and their field are still very good - as evidenced by their salaries being much higher on average than high school graduates.