Isn't a philosophy also a popular pre-law degree? A lot of these sorts of articles neglect to account for the actual reality of how these degrees are used.
What is your definition of underemployment?
The definition of underemployment is based on the kinds of jobs held by college graduates. A college graduate working in a job that typically does not require a college degree is considered underemployed. This analysis uses survey data from the U.S. Department of Labor’s Occupational Information Network (O*NET) Education and Training Questionnaire to help determine whether a bachelor’s degree is required to perform a job. The articles cited above describe the approach in detail.
47.1% of people with a philosophy degree are working in a job that does not require any college degree.