Shigeru Ohmori's earlier job as a map designer on Pokémon Ruby and Sapphire inspired the Pokopia concept.
While considering new directions for Pokémon, Ohmori reflected on his earliest work in the series. Designing maps had made him think about how appealing it could be for players to create and cultivate their own Pokémon habitats.
That idea became a foundation for Pokémon Pokopia, whose world is shaped through construction, gardening, restoration, and cooperation with Pokémon. The connection is therefore more specific than simply saying that Ruby and Sapphire inspired the game: Ohmori's map-design experience directly influenced the habitat-building concept.
Ohmori later served as the game's concept and senior director. His earlier map work helps explain why shaping environments is central to Pokopia rather than being a minor side activity.