I wonder if it's even worth trying to define a person's personality? I've been following this research for a while now. Almost all the studies I've seen have substantial flaws in their scientific methodology, such as small sample sizes and selection bias, among other issues. Don't even get me started on the replication crisis in this field.
Regarding theories like Jung's introversion and extraversion or the subsequent personality models like the MBTI and the Big Five, while they have been widely used and studied, there's ongoing debate about their reliability and validity. There's substantial evidence for the general reliability of the Big Five, but it, too, has faced criticism.
I got a sigh of relief when I finally discovered that Myers-Briggs is partly broken. It's designed to not offend anyone by avoiding measuring neuroticism so it's "work-safe". I had been struggling to understand how people were able to understand personality defects of out of the Myers-Briggs system and then eventually it became clear that it doesn't do this, it avoids measuring neuroticism, and worse than that it's on shaky ground because it does a poor job of typing people anyway because a persons personality can "shift" around over time. I'm still new to the Big Five though, I've only skimmed the surface of it, but at least it measures neuroticism and should plausibly give you better insight.
A big problem with Myers-Briggs is also that it expresses everything in terms of binary categories. That makes it easy to communicate your type, but also comes with less precision.
Big Five avoids this, but it's also difficult to communicate your Big Five results concisely.
Imagine a relationship in which one person can read the other's mind. This is the power of gods: They know our thoughts, but we don't know theirs. The only rational conclusion is total submission to their will, or to the will of their representatives. The offer of such a power, even to a severely limited extent, is appealing enough for people to part ways with their money and natural skepticism.
Can it be beneficial? A list of categories that seems authoritative and scientific but is open to interpretation can give some people a sense of comfort that they belong in their "place" within the organization, that there are other people facing similar experiences, or that they are not personally at fault. It can give a beginning manager the confidence to interact with colleagues and subordinates by means of a formula.
Can it be harmful? Sure, it opens people to manipulation and bias, or persuades them to give up their agency.
The only help I can imagine is for self discovery: it maybe gives one a handle on where to search for ideas, solutions, plans. At least that's how personality tests work for me - I enjoyed for instance the Sparketype.
Regarding theories like Jung's introversion and extraversion or the subsequent personality models like the MBTI and the Big Five, while they have been widely used and studied, there's ongoing debate about their reliability and validity. There's substantial evidence for the general reliability of the Big Five, but it, too, has faced criticism.