>>34674286Because almost literally everything can learn Double Team, and if used on a bulky enough Pokemon it becomes invincible. You're forced to run never-miss attacks, which have two problems:
1: Most of them suck.
2: They're poorly distributed.
The only one worth mentioning is Aura Sphere, so if the DT user isn't weak to Fighting, you're fucked. Basically, it's overcentralizing because it forces you to run a select few Pokemon to counter something that, I remind you, can be used by ANOYNE.
Zap Cannon, on the other hand, is an attack that only a handful of Pokemon (who aren't all that good to begin with except maybe Zapdos) can use, and only has a 50% chance of hitting. If you want to increase those odds, you'd have to blow a turn or two to use it. And even if all is right in the world, the opponent can just switch to something that's immune to Paralyze, or Zap Cannon itself. You can't do that against a Double Team/Minimize user.
