Mario is a platformer. Its limited by its very nature. You're playing almost the same game throughout its history, more than any other franchise. Ratchet and Clank would not be given a second look if not for the fact that its a sony game. Its a rote and silly jumping game, doing nothing of value or worth.
No, sequels are never meant to deliver more of the same. Why would anyone want another game doing the same things the previous one did ? All the masterclass games throughout history are remembered when they did something extraordinary, not when they did more of the same. Why even make a new game if you have nothing to say and just repeat the previous one ? Sequels that follow this formula are mediocre sequels.