The fact that it suits you as an anecdotal success is, really, little more than astrology and general cold reading, just digitized. Anyone can give an incredibly detailed essay yon your personality by doing little more than giving a second glance, just see Derren Brown's incredible cold reading trick that blows them all away as proof.
When you answer questions like 'yes I like to be alone' 'I find myself in my own world' 'i don't like to work under pressure' and 'I prefer to take a back seat' - It's hardly a surprise that the results come back saying
'You are somebody who likes to be in their own world, unless there are some external sources of pressure. Typically you prefer to take a back seat in these matters'
From there it's not hard to extrapolate with high probability of success that:
You are a creative individual who applies this in all aspects of life, from work to relationships and even the bedroom. You prize loyalty but try not to push this agenda, giving friends the freedom they usually desire from your intense love of the search for knowledge around you
And so on. The intent may have not been to trick people, but the outcome is little more, at the end of the day.
There's no actual new insight being reported in the test, it's just structuring your own thoughts about yourself that you manually input, into lengthy paragraphs - which is nice in its own way (Mine was basically 100% accurate when I tried it as an INTP and helped me explain my weirdness to some people) but it is important to accept that it's not much more than hocus pocus in its methodology.
Because of this, more importantly, one should not let the test define you. as many people do. By looking at it agreeably and unconditionally, a person is subject to establish themselves as that for life, but as others have pointed out, we are more complicated than that. My sister was once an extreme extrovert and now she is far more in line with introversion. Almost everybody who takes the test gets a different result six months later precisely because environmental experiences, surrounding friends and more changes us over time.
One might find the perfect INTP woman, but if they are made to believe the love is because she's INTP, when she inevitably shifts to, say, ENFJ, they;re going to resent the change and everything will fall apart - because the person in this story has defined them on faith as one state of personality.
Remember, you are not JUST 80% Introverted, for example. You are also 40% Extraverted. You are not only 77% ENFJ, you are 70% ENTP, 30% ESFJ, 56% INTP and so on. it only takes a little nudge in life experience to change you from ENFP to ENTP in this example.
But again, there's no legitimate science behind it - lots of reading on the subject out there and I think there are some modern alternatives that may be more legit