>>13566872There is an "anything goes" tier, it's called Ubers. You can use literally anything in that tier (things like Double Team might still be banned, idk, but all Pokemon are fair game).
The point of every tier EXCEPT Ubers is to be balanced. So for example, if there's a Pokemon that is so good that you would have to be stupid not to use it on your team, then everyone would use that Pokemon and the metagame would revolve around beating that one Pokemon. By banning that Pokemon you create diversity and allow more viable Pokemon to exist.
A good example of this is Garchomp in Gen 4. Back then, Garchomp with Yache Berry was so strong that it was guaranteed to get a kill when it comes in no matter what you did against it. The metagame largely revolved around controller your opponents Garchomp and minimizing the damage it did to your team. It wasn't fun. So they banned Garchomp, and the metagame suddenly got more diverse as a result. Flygon became a viable Dragon, Salamence and Dragonite gained popularity, walls like Porygon2 were suddenly useful, and a plethora of frail sweepers that got outsped by Garchomp were once again possible to use effectively (Lucario, for example). Removing Garchomp opened things up significantly and made a greater diversity of Pokemon and strategies viable. And of course if you still wanted to play with Garchomp, you could just play Ubers.
What you need to understand about the tiers, as well, is that they're there for the benefit of all Pokemon. If we had no tiers, and you wanted to use your favorite Pokemon - Chatot - on a competitive team, then you're shit out of luck, because people will be using Mewtwo and Kyogre against you and Chatot will die instantly whenever it comes in. With tiers, you can simply play in NU if you really want to use your Chatot without fear of him being completely outclassed and useless. Tiers provide options, and allow you to use whatever Pokemon you want in an environment where they can be competitive.
