After reading the Vox article and how MB is outlined I think perhaps I misremembered which personality test I took. My test included endless questions asking how you feel about or would respond to certain situations. Similar questions came up again and again, worded differently or with slightly different scenarios. At the end of the test you were given a chart showing where you fit into the different 'personalities'. Some of us were more or less evenly distributed across all personality types (perhaps as much an empathetic person as a logical person as a rule following personality), or you could be heavily focused in one area.
The benefit as I saw it was that sitting in the room, you saw that while you might be a rule follower and data driven ("Of course we'll just change how we do everything tomorrow because management says that is the new way!"), your co-worker might be highly empathetic and a visual learner ("You can't just throw out how things are done without asking for feedback, allowing people to first express their concerns, etc.!"). Once you knew how you and your co-worker viewed the world differently, you understood that to influence others, you had to speak in terms that they understood and communicate more in their preferred learning manner.