Well, there isn't a straightforward successor to Dragon Ball Super. Different people might consider different manga to be the 'next big thing'. For instance, Demon Slayer has been highly regarded for its unique story and art style.
There are many manga that have come after Dragon Ball Super, depending on your interests. Some popular ones include My Hero Academia and One Piece.
It's hard to pinpoint a single manga that directly follows Dragon Ball Super as it depends on various factors like genre and popularity. However, series like Jujutsu Kaisen and Chainsaw Man have gained significant traction recently.