Quoted By:
The problem is not only the powercreep and new flashy offensive threats everyday, but also new mechanics/gimmicks every gen (1) and overdistributed move buffs (2).
(1) not even talking about megas here. You had to be prepared to control hazards and use them yourself, to phaze and deal with baton passers, to deal with weather teams, you need a full stop to setup sweepers, etc. then GF adds trick room and you have to be prepared too, easy-to-use Genies or Talonflame to save the fools asses/be a staple in every team/make some pokemon never be OU again just by existing, new items every gen, even a new fucking type instead of balancing the types we already have...
In a match where each party has only 6 mon with 24 moves in total, how can you be prepared for everything? It will be an increasing matter of match up each gen that passes and new mechanics are added.
(2) Fuckin Knock Off. How much pokemon did, say, Jellicent wall that it doesn't anymore thanks to that retarded buff and distribution of Knock Off? What about scald: 30% of burning, the ones immune are probably weak to the move.