It’s the same thing with a game like Far Cry. The fundamentals have stayed the same for 10+ years, but they add a few things on top to make it look different to anyone that isn’t paying attention. It’s why this saying exists: “if you’ve played one Far Cry game, you’ve played them all.”
Pokémon is a huge universe that has potential for all kinds of stories. But they’ve stuck with the same thing for 20+ years.