I'll admit that I have a fondness for personality tests. I find them interesting, but I have no delusions about their ability to contribute to any meaningful analysis of one's life. That said, I don't think it's helpful to compare a system that is based on when you are born, to one that is based on answers to a variety of questions about how you would respond to different scenarios. The ways these tests are used by employers is exploitative, but that doesn't mean that there aren't interesting things to glean from categorizing trends in how people respond to these questions.
Astrology is uninteresting because it lacks even this barest of links to what you might be experiencing as an individual, but personality tests at least try to group you with like-minded groups. There are so many valid criticisms of personality tests, but at least they try, whereas astrology is lazy in so many ways.
anyways if you can't tell I'm an INTP and therefore always trying to understand things at a deeper level and probably better than you and or bad at communicating or something.
According to this we could validate astrology if we let people, after questionnaires and research, to determine their own sign.
I was interested in typology during my tumblirina phase but even in socionics, a system developed by soviets, I found problems that I believe are Jung's fault: the inconsistency of his dictomies, and building a system based on the individual and their mind as entities isolated from the environment.
In the worst-case it is determinism, reinventing human nature but with 16 different flavors.