Good points for sure.
For me, the point of it is simply to satisfy my obsessive thirst for knowledge. I love having a puzzle to work on and expand upon (Ne), and it's even better if it helps me understand myself better (Fi), or has a practical purpose (Te).
It's impossible to objectively look at yourself, but it's important to try so you know what you need to work on.
You seem to be crossing MBTI functions and this other objective personality. Basically with Te vs Ti is
T is reasons which may or may not be logic. Its why dom Ti has ALOT of reasons behind everything they do. Its not a simple I just wanna go against the grain...I will tell you exactly why I am going against the grain.
Ti: does this person identity about these reasons and are they using Fe to see if others like these reasons.
Te: Are they using these reasons to communicate with the tribe and look for tribe validation...(does the tribe like my reasons).
This is based on objective personality site, not so much "practical purpose" Te and Ti have a practical purpose.
Te vs Ti
Fe vs Fi
Ne vs Ni
Se vs Si