Why did suit life on deck stop?

"The Suite Life on Deck" ended after three seasons because Disney Channel wanted to focus on new projects and give other shows a chance to shine. The decision to end the series was made as part of Disney Channel's regular programming strategy to keep its content fresh and diverse. The network wanted to provide opportunities for new stories, characters, and settings, and felt that it was time for "The Suite Life on Deck" to come to a natural conclusion.