Pokémon was never designed to be competitive. Basically, it was a simple rpg, strongly based on luck. It was an excellent rpg and it could have stayed that way but it took some assholes to develop it into a competitive one.
Because of them, developers are caught between the desire to make a good game and the "need" to please the competitive scene. That explains in my opinion the decline of the game: they had to add this damn fairy type to balance dragons, when it was really cool, lore wise, to have one type stronger than the other.
Similarly, some pokémons only exist for strat. The multiplication of shitty legendaries (the genies trio) is only there to please these players.

For the sake of pokémon, competitive players should go to other games designed for that, trading card games like HS or Magic, and leave pokémon for those who just want to enjoy a good rpg.
And maybe that way, Game Freaks will be able to propose a redesign of the combat system, profoundly change the license and make a game that would be for pokémon what BOTW was for Zelda.