RG3 is marketing gold. Cousins is an average, boring QB. But he will win 3-4 more games than RG3, and that's being friendly.
RG3 is the perfect example of what's wrong with society awarding someone all sorts of praise and power, before he's earned it. He had a solid rookie season, but coach was powerless to take him out in the playoffs when he was injured. he sits out that game, and he arrives hungry and disciplined when season 2 starts. No, he gets injured, returns too soon (forced that too) and gets injured more.
At this point, RG3 could do fine in a new system with a new coach. Send him to Andy Reid and he does very well and he's 11-5.