The Legend of Zelda: Tears of the Kingdom was practically finished in 2022, according to the game's director Eiji Aonuma, but was held for a year so that Nintendo could better polish the game before its release.
In a new interview with The Washington Post, he said that essentially all the working parts for the game were done, but it received a delay from a release in March of this year to make sure that everything was at the team's required standards.
Considering The Legend of Zelda: Tears of the Kingdom is currently receiving immense praise, it seems that extra time to simmer may have really done the game some good. It also helped to likely ensure that there were as few bugs as possible with the potentially limitless possibilities of some of Link's abilities this time around.