Why 6...e5 in King's Indian? I'm a hobbyist chess player, mostly playing online correspondence. I often play the King's Indian defense as Black, but there seems to be a key idea in the opening that I'm missing. Specifically, I don't understand why 6...e5 is so commonly played in so many variations, for example:

[fen ""]
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1. d4 Nf6
2. c4 g6
3. Nc3 Bg7
4. e4 d6
5. Nf3 O-O
6. Be2 e5


It seems to me that in this position by playing 6...e5 Black blocks his own fianchettoed bishop, and given that White frequently pushes d5 later on, the diagonal is unlikely to reopen up any time soon. It seems to me that something like 6...c5 would be a much more natural move, logically setting up a queenside attack with the central pawn chain supporting the dark-squared bishop on the long diagonal.

Clearly I'm missing something here, given 6...e5's popularity relative to 6...c5. So my questions are


Why is 6....e5 so much more popular than 6...c5, and
What is Black supposed to do with his dark-squared bishop after 6...e5?
It is good to think more concretely here. After move like e5 three things can happen. White can take on e5, white can play d5 or black will one day play exd4 himself.


Taking on e5 never wins a pawn and creates a hole on d4. For good reason not very popular
With d5 your bishop is now bad, but the position for black is good, easy and funny to play. An attack with f5 f4 g5 h5 g4 Ng6 Nh4 is very dangerous. Bishop often joins the attack in later stages from h6 and is often use on f8 till its time to hold the queenside for a little longer. Also maneuver Rf8-f7-g7 us typical to protect 7th rank and attack at the same time. Find games of Nakamura how he murdered some 2700+ players just rolling on the kingside.
Tactics say it is not so easy for white to achieve exchange on d4 under good terms. After 7...Nc6 there are no useful moves for white and pressure against centre is already too strong. Popular d5 goes to (2) and Be3 runs to Ng4, even if it is also variation.


So there are three good scenarios for black after e5 and in comparison to some Maroczy bind or benoni structure I think they are both better and more interesting to play.

Note1: Many c5 style players play c5 already on move 2, by the way.

Note2: Calm players with no intention of attacking don't play kings indian in the first place, playing Nimzo Indian, Slav etc...

So everybody wants to play e5 and win!