Re-enrolling and completing a bachelor's degree has positive effect on annual income. Returning to college to earn a bachelor's degree leads to both an immediate increase in annual income after graduation and an increase in annual income growth each year after graduation, according to an economics researcher. Source 3v.
I'm sure the statistics tells us this, but from my personal experience, I have a BA, but my economic status is only slightly above those who don't have my degree. Thankfully, with my degree in early childhood education, I can find a job that will at least keep a roof over my head anywhere.
I'm not surprised that an economics researcher is seeing a positive correlation between getting a Bachelor's degree and an increase in wages. Many white-collar jobs, when hiring for those, have a Bachelor's degree as a requirement, and most white-collar jobs have a higher income range than blue collar jobs (Which typically require a high school degree, an associate's degree or a certification).
But that doesn't mean we should entirely discredit the trade schools and specialized hands-on professions. Wages for those seem to have been raised much higher lately as demands change. Just as an example, after the major freezing storm in Texas, plumbers and other contractors were in high demand, so wait times and prices were extremely high.
I think a degree or some qualification is useful for personal development, depending on ability. In my line of work, the minimum qualification is a master's degree in computer science or the equivalent.