I don't mean to be rude, but could you source that Truity claim? When I look
here, it says "Based on a Big Five assessment developed by psychological researchers, this inventory will tell you everything you need to know about what makes you, you." and anywhere else I look it's about the same. Though of course, Truity isn't the scientific community. The measurements are refined and maintained by psychologists, not Truity.
I get what you're saying, but I'd like to counterpoint and say that there's potentially even more you could learn about yourself from the big five. Like, there's some real eye opening revelations I've gotten over the years by reading about the traits and what they really indicate.
Did you know that extroversion isn't actually strictly related to sociability? It's believed to be a sort of 'potential for positive emotion'. Extroverts, hence, get easier 'hits' of positive emotions, which can drive social behavior; conversation makes for easy dopamine hits, but they don't have to be social to get them. You could be extroverted and never talk to a person, by for example engaging in a lot of worldly activities (surfing, sky-diving, etc). Of course, if there is a person there is an easy hit of dopamine, so... An untalkative extrovert would be unusual, still.
For an introvert, the potential for positive emotion is significantly lower, so to experience anything ecstatic, they have to do something they care about quite a bit. This motivates long-term goals.
Extroversion indicates a desire for a breadth of activities, whereas introversion indicates a desire for depth in their activities.
A lot of the time, I see introversion/extroversion confused with anxiety due to a poor understanding of the traits. So, a lot of introverts will be played in movies as stuttering, anxious, not sure how to make friends, etc. An introvert can, however, be the most charming and confident person in the room. The real trick is, they don't care about socializing as much. Not caring is vastly different from being anxious. It's "Yeah, I could make friends if I wanted to, but eh. The drinks taste nice though." versus "I don't even dare go close to people!"
(I'm, of course, both introverted AND anxious, so... I kind of fit the introvert stereotype, lmao)
It also leads us to the existence of anxious extroverts, who may think they're introverted because they're too scared to make contact with people, locked inside their own heads, parts of them screaming to get out of their house, the other part screaming for them to stay inside.
Soooo... Yeah. I like the big five a lot!