They don't at all. At typical companies, their salaries are maybe a bit higher than software engineers. At top companies though, their base and bonus is the same, but stock is about half (unless you're a core DS or have an AI/ML PhD). Also, 4-5 years working on a PhD could have been spent gaining experience as a software engineer, which means that all total a data scientist at FANG will make $100k to $250k per year less than a software engineer at the same age.

do they? in the article 136k w/ 4-6 yrs exp really isn't a lot, especially since it has a higher % of PHDs.

i became a data scientist because I love that type of work. I like solving puzzles and diving deep into data and helping to drive decisions. I imagine others want to be / or have become a data scientist for that reason.