Also :-
1..Black has a pawns majority on the queenside 3 vs. 2
2..Black has a control on the dark central squares
3..black has the "e" semi open file
4..The Benoni Defense is designed to provoke White's center to become overextended and establish a strong point at d4 & e5
The Benoni defense is designed to sacrifice one of black's flank pawns in order to hopefully accomplish one or more of the following:
1. Gain the upper hand on development of pieces - which was white's starting advantage.
2. Divert one of white's key center pawns to the flank.
3. Focus white on protecting his pawn, when he should be developing pieces and controlling the center. Sometimes this will lead white into some bad positions. For example, playing 3. Be3 indeed protects the pawn for the time being, but it also blocks white's e pawn. Now white is without both his key central pawns!
But the best possible outcome of white's obsession with saving his pawn is falling for The Old Benoni Trap. Watch this video to see how razor sharp the Benoni can be in terms of its tactics.