There was a very brief exchange about type indicators between the well-known Niels Pfläging [1] and Alexandre Foisy-Geoffroy [2] on Soapbox Prime on Soapbox Prime, I mean LinkedIn [3]. I think both are wrong, but since I also think that argueing on a public plattform on the internet is like taking part in a self-mutilation contest — even if you win, you are still mutilated — I did not say a word. I'll write my piece here, in the safe recluse of the Gemini Space.
[2] Alexandre Foisy-Geoffroy's LinkedIn profile.
During my career I participated in quite some assessments and other opportunities to get my type indicated. So here's my take of type indicators. Type indicators are intended to be generalizing descriptions of persons, such as "Harry is a Gryfindor." They are more or less founded on psychology and related arts and sciences. I write "arts and sciences" because not all things discussed in books about type indicators stand up to scrutiny Sir Karl Popper would accept as scientific.
For my intents and purposes I'm not really interested in the scientific merits of type indicators. Not only because I think they are all wrong in one way or the other, but also because their utility does not depend on being true. Most attempts to divine what type of person you are walk you through a set of questions with a defined input range. Thus these questions already introduce a certain granularity in results. Your answers to those questions put you on some sort of spectrum in one or more dimensions. Some ranges or sets of ranges are then defined as Gryfindor or Hufflepuff. In a nutshell, type indicators bunch people together by the similarity of their answers to some questions. You are vanilla, I'm chocolate. So far, so obvious.
It is equally obvious to me that you therefore can't draw any conclusions about behavior from type indicators. That is, type indicators are not predictive although some may be descriptive in some sense. That sounds damning. And it is, but still I maintain they have utility. They are useful as conversation starters and point to distinctions that may be worthy of discussion. While I would never accept a statement such as "She is ENTP, therefore she is like this or that" or "She will do this or that." I would accept a statement such as "She is ENTP, I'm ISTJ. We should discuss our outlooks on customer interaction." That's the utility.