>>32410742It's just a natural progression of the game. To beat/counter something strong, you need something else that can stand on equal ground with it. Repeat this process over the course of 20 years, and suddenly things from 20 years ago probably isn't as good as things made in the present.
It's the same in the main Pokémon games too: Gen I/II Pokémon generally have lower and less specialized stats than ones from later gens.
