During the Pokémon Sword and Shield video game era, Greninja received most of his votes from fans during the Pokémon of the Year 2020 voting system. As voting results, it had finally become the #1 most popular Pokémon with fans worldwide, making it the winner of the Pokémon of the Year 2020. However, unfortunately, for most fans, Game Freak denied their request from them, so they have instead foregone the inclusion of Greninja for any of the Generation VIII Pokémon mainline video games, like Sword and Shield, the Isle of Armor and the Crown Tundra, making it unavailable in and untransferable to those games, and I would think that the most fans didn't care if Greninja had won Pokémon of the Year 2020. So despite being the Pokémon of the Year 2020 upon most vote from fans, I wonder why you think that Greninja was not in any of the Gen VIII mainline video games? Please let me know, thanks.😉