What is the point of 2. d6 in the Sicilian?

Ok, so after 1. e4 c5 2. Nf3 d6 id the most common move here. Wikipedia claims that the reason for this is so that black can play Nf6, forcing Nc3. However, Nc6 does the same thing without blocking the bishop, without the potential for the backward pawn on d6 and developing a piece. So, what is the point of 2. ...d6?

...Nc6 commits the knight to the square when it might want to come to d7 and ...d6 immediately opens the bishop, so those may be the reasons to want to prevent e5 with ...d6. However, ...Nc6, ...d6, and ...e6 are all main lines and are really about equally good, but I guess ...d6 is more fashionable.

d6 is to prevent e5, some other ways of preventing White's aggressive e5 is Nc6, e6 - (usually Qc7) in that variation..

One reason may be that 2...Nc6 allow for 3...Bb5, a variation a lot of players don't want to get into.

But really, either way, they are both solid. 2...d6 and 2...Nc6 just lead to different types of games, and the key is to find the one you feel most comfortable with.

d6 also puts the pawn on a square where it's defended by e7, which is important seeing White's usually about to half-open that file