The Pokémon Company Having ‘Conversations’ About Its 'Constant' Release Schedule - IGN

Gamefreak cannot keep its historically small team size while trying to make large, open world titles that release annually

Define "small". For Sword and Shield they had around 1000 workers, according to Ohmori, the game's director.

With 200 being from Game Freak, some from Creatures Inc. (they make the 3D models and send them to Game Freak) Debugging and Quality Control is externalized

So, yeah. The number being close to a thousand, that of course includes all the different functions like marketing and PR and everyone that would be associated with the game ahead of release. But I think at Game Freak, really the core team of people that worked on the game was around 200 people. And of course, Creatures is another partner company that develops 3D models of the Pokémon. There are various teams that handle debugging at our partner companies as well. So there’s a lot of people involved and I think in terms of just the sheer number of the most resources required to make something happen for the development, it was definitely more on the graphical side of things.

https://www.polygon.com/interviews/2019/10/24/20929597/game-freak-explains-the-1000-staff-missing-creatures-and-leek-size-of-pokemon-sword-and-shield

So it's not like Game Freak does everything for the game. They don't have to do the 3D models that will be used in the game nor debugging

And they hired more for Scarlet and Violet iirc