Comment by PotatoEngineer

The trouble with dynamic terrain--and especially walls--is that it's hard to place a cost on destroying walls to get to where you want to get. A* is simple enough, but adding tactical considerations to it is much harder. It's a balance of "I will have a harder time hitting the opponent" vs. "I get to do damage right now, before my opponent gets to do any more tricksy maneuvering."

C&C was particularly terrible with walls; if there was any path at all, it wouldn't destroy walls, which made it easy to ambush.