TheGreatLugia
Banned
The decline being talked about in this thread happened way before YW and Gen 6. Based on what I've seen things just went crazy during 4th gen due to the DS and after that generation there has been decline.
I want to say every generation has sold less copies than the previous one if you exclude Gen IV, which might slightly match up with every Nintendo handheld selling less units than the previous one if you exclude the DS. I could be misremembering the sales numbers for a few entries, though.