This whole Charizard X vs. Charizard Y argument seems kind of silly. It's really team dependent. Charizard Y absolutely needs support and from a purely offensive perspective just punches giant holes in the enemy team. In exchange for the additional support he supplies Drought. I would think in order to use him effectively you would need someone to control hazards as well as some Pokemon who benefit (but don't necessarily rely on) Sun. Basically, if you run Charizard Y, you'll be building a lot of your team around him.
Charizard X is just your standard late game sweeper, with some better stats and offensive typing than most. He doesn't need support, and he doesn't provide it. He's just a late game sweeper. Not much to say here, really. We know how he works by now.
The point is that comparing these two is really difficult. Of course Charizard Y is going to outperform Charizard X when you have a whole team built around it, getting rid of SR, abusing Drought, and dealing with the plethora of checks and counters. They perform such different functions that it doesn't really matter.
Charizard X is just your standard late game sweeper, with some better stats and offensive typing than most. He doesn't need support, and he doesn't provide it. He's just a late game sweeper. Not much to say here, really. We know how he works by now.
The point is that comparing these two is really difficult. Of course Charizard Y is going to outperform Charizard X when you have a whole team built around it, getting rid of SR, abusing Drought, and dealing with the plethora of checks and counters. They perform such different functions that it doesn't really matter.