Nintendo's Senior Managing Executive Officer and Corporate Director Shinya Takahashi reiterated how it was "inevitable" for software development cycles to increase as hardware advances, but at the same time thinks Nintendo is "succeeding" in its efforts to shorten overall development cycles by "steadily improving the development environment".
This same question touched on how Super Mario Bros. Wonder was the "first new 2D Mario game in 11 years" and although it's been this long between releases, according to Takahashi "it is not as if Super Mario Bros. Wonder was under continuous development for nearly a decade". The "long gap between" the releases was because of various initiatives and studies.
Although this is the case with the latest Mario game, Nintendo has experienced some incredibly long development cycles this generation with games like The Legend of Zelda: Tears of the Kingdom and the upcoming release Metroid Prime 4: Beyond, which was even restarted at one point. This follows a comment Furukawa made about Generative AI, mentioning how it's "open to utilizing technological developments" but would continue delivering value that "cannot be created by technology alone".
