KID is messy chess, but it has been sufficiently studied to the point that it has defanged a lot of its ferocious reputation. engines especially have introduced new defensive resources for white. It's still an excellent choice for must win games though or those that dont mind to trade some objectivity for a messy long term battle.
chess is a lot more preparation now than it was during the days of Fischer and Kasparov, and KID allows white an enormous variety of ways to push for some advantage, Engines are not psychologically swayed by its complications (although a good player will keep in mind positional horizon effect possibilities, esp with blacks massive pawn storm). When you catch someone by surprise with it? KID can be great, but when you play someone that knows what you are likely to play like Super GM's do with each other, KID is HARD, so you simply dont want to play it too often even if its part of your repertoire.
Two questions on King Indian Defence.

Thank You For your answers.
@najdorf96. I have no issue... As said i am just curious. As I read and learn about chess i started to get mixed info on KID. I would say, a mixture of awe and mistrust. Of both scepticism and immortal victories by black. And having played with the databese a bit I have spotted KID statistically scores very bad, engine also does not like it. KID seems to be just as good/bad as scandinavian defence which is not surrounded by a romantic aura.
When i was a total beginer, and needed to find my answer to 1.d4, i wanted KID to be my primary weapon. Foolish me! KID is very beginer-unfriendly. Now I aim for Tarrash defence. The structure with pawns on e6, d5 and c5 and rook to go to c8 is pretty universal, and definattely brings me better results.
@thillerFan and @pfren
I knew the position(s) You have shown me. Not that have studied or analysed it, I merely knew about it - taking exd4 is one of options i mentioned. But may I ask You isn't this position ( or the one with pawn rather then knight on c6) just better for white?
I mean there is nothing TERRIBLE about black - but he has just given up his central power, white has spatial advantege and the Marozy bind ( which in sicilian is usually avoided by black), and smooth development ( pleasant choice where to place his c1 bishop - all aviable squares look reasonable). All white needs is to decide where the dark squared bishop goes, place the queen on d2 ( or mayby c2?!), centralise rooks and the game playes itself. I can't really see a plan for black, save the obvious need of completing development, which is not that easy due to space disadvantage.