I have never played platinum, but from what I gathered it is significantly improved compared to Pearl/Diamond. Those are really painful to play.

They’re really clunky and repetitve, but the worst part is mon distribution. There are barely any fire types in the games, to the point the Fire-Type elite 4 has only 2 in his 5 mon team. And one of them is the evolved fire starter. There is literally no other fire type obtainable at that point.

They decided to keep most of the diversity in the post game (lots of old species that get a new evolution mostly) so until you get there it feels like you’re meeting the same twenty different pokémon over and over again.

Bonus : Diamond has one dark-type easily accessible before psychic gym (which is already well into the game). Pearl doesn’t. Its only dark-type comes in very late game. It’s like nobody checked these games’ balance.