Please stop typing so many people IEI.
IEI and SEI and EII, all three of these types get pegged as the 'average humanitarian bland type.' Ie, the general banal/bland psychology 101 aw-shucks loveable loser get typed as that. Most people when they take the test will get those types. Because seriously, who ISN'T interested in their own thoughts and feelings compared to the world around them? Furthermore, not many people are realistically interested in their thoughts over their actual feelings, it doesn't make sense (also it doesn't make sense to dichotomize those things as if they were opposites, either) You feel a certain way because you think a certain way, and vice-versa. Also, to even take a personality test to begin with, you are going to have a bias for classical introversion. (You want to find out about yourself primarily as we're all intrinsically selfish in that way, as opposed to how you *really are* when lined up with other people, which is what socionics actually explains.)
Your type exists primarily not in self-identification (which its all too easily for virtually *everyone* to get the aforementioned types) but in relationship to others, and then you kinda really see the effect of them taking place.
The truth is, there's probably less IEIs than we think because nobody on the forum really gets along, we have a 'business-like' respect for each other but for the most part, we argue and get on each other's nerves and don't really relate all that closely with one another, and we also tend to bring out the more 'nagging' aspects of our psyches. But I actually like this, because it shows there is a good diversity of the types.
You are not IEI just because you have a rich inner world, you like poetry, art, etc. You like fantasy novels, again- that's not IEI, it's just of course, due to everything else connected, IEIs have a greater tendency to like that stuff, but it isn't what it's about, it's a personality theory, it's how you mesh and relate to other people, it really has nothing to do with your hobbies or what you really like to do, by yourself- because most of us have probably encountered the situation where we found somebody who had our exact same hobbies and we didn't get along with them, because of the personality clashing. And as for self-identification that is always innately misleading. (Have you ever thought in your own ego or head that you were a certain way but in truth, it was the exact opposite?) All of these theories try to balance how you see yourself compared to how others see you, and how that makes you line up with certain people.
And it's very very important in society because if these internal views aren't met, then conflict brews under the surface, subconsciously.
It's more subtle and nuanced then you think. You can't think 'oh he's an aggressive manly straight guy jock so that means I am going to clash with him' as it's just not general or stereotyped like that. You can't connect the dots where there isn't any.