Pokémon is an RPG, not Skyrim or Breath of the Wild
That said, games like Tales and Dragon Quest make Pokémon look like a fucking joke, there's really no excuse for how minuscule and boring the overworlds in Pokémon games are. I bet if you measured in terms of steps, Alola would be very close to the size of previous games, and that's just pathetic.
But you can have a large overworld with lots to explore without turning it into some freeform game with real-time combat and survival elements and action gameplay.
