>>13421919After that, they started to branch out. They made stuff like Girafarig so people could say "there's a giraffe Pokemon now" and then Wailord so people could say "the biggest Pokemon is a blue whale". This was fine in concept, but in execution causes a major problem: how can a blue whale Pokemon exist with an actual blue whale? Pokemon are obviously fantastical versions of certain source matter so it no longer makes sense to place fantastical fauna next to real fauna. Now that there is a Pokemon for every animal, they don't really know where real animals fit. Did they die out? Did Pokemon make them extinct? Did they evolve from Pokemon? This can't be because it's established that Pokemon have been around unchanged for hundreds of years.
So this issue is that originally Pokemon were designed to be HYPER animals, like cryptids; rare but powerful yokai that appear only once in a blue moon. Now that there are so many, and so many that are analogues to real-world flora and fauna, trying to fit the two together simply cannot work consistently until they pick one option. Either they exist too, which makes them unappreciated in comparison to Pokemon, or they don't exist, most likely because of Pokemon. Gamefreak don't want Pokemon to ever be portrayed in a bad light, so they simply won't decide.