I think White's advantage here is one of the soundest and least theoretical evaluations in all of chess—and one of the most important to study and understand.  It is important for both sides to understand the value of pawn majorities and minorities.  Learning about the Carlsbad structure is a vital part of anyone's chess education.  I would also suggest that this is an opening White can expect to play for life without being caught out by stunning theoretical reversals (which is what I really meant earlier by way of asserting that White's advantage in the QGD Exchange is among the least theoretical evaluations).

Having said that, I really like the ideas for Black against in the QGD Exchange offered in Dangerous Weapons: The Queen's Gambit.  I don't think they reduce White's opening advantage significantly, but I like Black's activity...

If White hasnt played Nf3 it is dangerous for Black - Nge2 gives White a lot of nasty ideas. Therefore Black usually avoids the classical move order and plays 1.d4 Nf6 2.c4 e6 "threatening" the Nimzo - if White goes 3.Nf3 Black may retourn to d5 as the exchange variation is no longer a dangerous option for White.