Well, Faeries don't have to be quite so stereotypical, actually, but I'll get to that in a moment.
So the first thing to do is to remember that Faeries don't have souls, but rather things akin to rulebooks. They're always playing by their rulebooks, rather than by their desires, though only highly cognizant Faeries really know this, with incognizant and narrowly cognizant Faeries usually pretending to have desires so well they fool themselves.
Because that's most of what Faeries do right there. It's the reason they have Pretenses instead of Abilities, and why you notice them being more types than characters. They pretend, they play a game; people sometimes dislike Faeries because they, in a way, aren't really the characters they appear to be, and playing a Faerie is actually more akin to playing a mentally unstable roleplayer who thinks that the roleplaying game is real and the rules of the game are the rules of reality (with higher levels of cognizance really being more like higher levels of sanity, in that sense, as the character detaches more and more from considering what it does to be truly real). A Faerie who seems terrified isn't actually afraid, but acts like it is, and in some cases is acting so well that it convinces itself that it really is afraid. A Faerie who is sad isn't really sad, but is roleplaying a sad character. So on so forth.
To take the analogy a bit further, incognizant Faeries are people who have no life experiences except for playing the roleplaying game, narrowly cognizant Faeries are people who lead normal lives but have the aforementioned mental instability that causes them to think the roleplay is real, while a highly cognizant Faerie is like you or me playing a roleplaying game, sane and capable of differentiating between the game and reality.
In the same vein, imagine roleplaying a character yourself. When that character grows as a person, it's almost never a result of you yourself learning a valuable life lesson and applying it to how you roleplay the character, but rather your character going through something and you deciding that it would be interesting or fun if the experience caused your character to develop in a certain way, so you start playing the character a bit differently.
This all ties into why Faeries are almost always types, as you call them, rather than characters. The vast majority of Faeries are incognizant or narrowly cognizant. You've spent your life growing up, learning new things, developing perspectives on the world, and figuring out how other people work. You're capable of being introspective, looking at yourself in the metaphorical mirror, and learning from your experiences and mistakes.
Incognizant Faeries are completely incapable of doing that; whenever something happens to them or they make a mistake, they don't think about how that might affect themselves, and they don't learn to avoid mistakes they've previously made unless the rulebook for the game they're playing has rules on how to change as a person. This means that in the vast majority of cases with incognizant Faeries, they seem like caricatures and stereotypes rather than multi-dimensional, developed characters; they were told how to pretend to be whatever their character is at their basest level, but they weren't told how to do character growth, so they turn out to be undeveloped characters because, can you believe it, they don't know how to develop characters.
It works on a similar but lesser scale for narrowly cognizant Faeries. They actually can learn from their mistakes, and their characters grow in a stunted version of how real characters grow and develop, learning from their mistakes and judging new experiences, but they still don't know how to be self-reflective, so they can't change who they fundamentally are (for example, a narrowly cognizant Faerie thief might learn to be kinder or develop new stealing techniques in response to anti-thievery measures, but they won't understand the concept of stopping their thieving ways unless the Faerie formed with the specific intention of pretending to learn that lesson). They also have memories of their previous "characters" and what those ones did wrong or right in regards to the role, though they always play the same role. (Seriously, John, the arrogant elf rogue searching for his kidnapped sister is getting really old! Play something else! "Never!")
Highly cognizant Faeries are the most capable of being true characters, because they're almost exactly like you or me as roleplayers, with the exception that they actually rely on their characters for tangible benefits unlike us, who just play for entertainment. They can have their characters learn lessons from things that happen even if they didn't expect those things to happen or plan for their character to develop that way; they can see what they did wrong from the outside and think "okay, I'll try this next time," and can draw on experiences other than the experiences of the character in that role; and, perhaps the biggest thing, they can grow "bored" with a role (which usually means that it would be in the Faerie's best interest to abandon it, because again they play the game for pragmatic reasons rather than for entertainment) and decide to change characters and play something else. Highly cognizant Faeries know all the bits and pieces necessary to play a multi-dimensional and believable character, and they aren't limited the same way incognizant Faeries are in not understanding how to pretend to change.
The analogy isn't perfect, because highly cognizant Faeries still don't have souls, but it's functionally identical, because highly cognizant Faeries both have rulebooks that are more complex than the average soul and a place to write corrections and, dare I say it, House Rules, if things don't work as expected.
