You can pick any set of axis you feel like and get similar results. “Do you like X? Wow you are an X person!”. So yeah, technically better than horoscopes, more like a “warm” reading where you tell a person what they told you earlier. But it’s entirely unclear why these axis are the right ones over a million other possible ones, if these are particularly stable categories in time and context, or if the harm of encouraging people to box themselves or others into specific stereotypes has any possible benefit to outweigh the obvious harms of simplifying stereotypes.
It's good questions. Here's why this axis is the right one in my opinion:
1) As I mentioned, it has a lot of statistically significant correlations, including to all the variables of the Big 5. Example: Surveys show that % of the overall population that is each type (like INFJ) is very consistent across time and populations.
2) Beyond that, youre right, there are a lot of personality systems with pros and cons. But Myers-Briggs has by far the must supporting materials, tools, ease of use, and so on. I think its the quickest to make useful to the average person.
3) I've found it really helpful as a lens for self analysis in my own life.