When 'My Career' mode made its debut in WWE 2K15, it was a hot mess. Extremely boring and repetitive grinding made the mode extremely un-fun and dry all around. WWE 2K16 and 2K17 made improvements by adding things like backstage interviews, the ability to interfere in other wrestlers' matches, starting rivalries, and more. But that wasn't enough to make the whole mode feel authentic and make players feel like they were an actual WWE wrestler.
One interesting way to improve 'My Career' mode in WWE 2K18 is to make it more engaging and interactive. Incorporate storylines, but with choices, somewhat similar to Telltale Games' series, where certain actions and responses will generate significant outcomes and consequences.
For instance, ambush a wrestler during an important match and then feel free to either explain your actions or not, all while carefully planning out your next move. Something like that would make the gameplay more meaningful and interactive.
It would be nice to create a female wrestler in 'My Career' mode and see how she'd do in the women's division.