The demands of the Triple-A gaming industry have forced development studios to use increasingly large teams to work on games. However, one of the most prominent figures within Game Freak has expressed a desire to work with a smaller team on games, due to the difficulties of managing so many people on a single project.
Junichi Masuda is a member of the Game Freak board of directors. He has worked on almost every Pokémon game, either as a composer, director, or producer. Masuda is currently working as a producer on Pokémon Sword & Shield, and his most recent stint as a director was on the Pokémon Let's Go games, which he stated would be the last time he worked in that role.
Masuda has expressed a desire to work with a smaller team on games, but the demands of the industry have no longer made this feasible. The staff of Game Freak was recently interviewed by Game Informer about the development of Pokémon Sword & Shield and the upcoming Little Town Hero, and the size of the development team was brought up. Masuda mentioned that he would prefer to work with a staff of around twenty people, as it's easier to communicate and keep ideas straight with a smaller group, but the reality of creating a game on the scale of one of the recent Pokémon titles makes that unfeasible.
Pokémon Red & Green were created with a skeleton staff of under twenty people, but the series grew in scope over time and the demands of each project gradually caused more people to brought in. The ever-growing roster of Pokémon in each game also became an issue, which is why the National Dex isn't a thing in Pokémon Sword & Shield. It makes sense that a director would want to work with as small a team as possible in order to better manage a project, but it's not feasible to create a project as big as Pokémon Sword & Shield with so few people.
Pokémon Sword & Shield will be released for the Nintendo Switch on November 15, 2019.
Source: Game Informer