Even in the systems where Black plays ...c6 and ...e6, there are certain variations where later he has to play ...e5 or ...c5 and accept an IQP- else he will simply watch passively.
IQP positions are a vital part of the game, you cannot "wipe" them from your repertoire.
I fully agree, and I also don't think that avoiding a common type of position is the best way to improve. But sometimes people have to find their way by making some mistakes
OK, if black wants no pawn structure liabilities, he can play the Benko. There, he has an ideal pawn structure, and active piece play, which is rather easy to master (although good endgame skill is required). But there is a small detail: He is down a pawn.
Agree, but under a rating on 2000, the pawn-down doesn't matter. The best player will win, and the black play is much easier to organize than the white counterplay. The worst thing about the benko is that white has several way to decline the gambit and fight for a positional advantage like the 5... b6, or even create a very sharp position with f3-variations.