I think Rock could be that, he just chooses not to. He sticks with PG-13 movies and he's always the good guy. Cena, on the other hand, has been willing to go outside of his comfort zone and do R-rated films and play characters who aren't generic cardboard cutout heroes.
It's the same as the difference between Batista and Rock. Batista wants to be an actor. Rock wants to protect his image/brand.
Even if Dwayne leaned into rated R stuff, or if Cena went to Dwayne… Cena out acts him. Cena would have crushed the Jumanji reboots.
Cena is INSANELY funny because his timing is elite. I firmly believe you’d struggle to make Peacemaker good without Cena’s timing, because while the writing is funny, it’s Cena that carries it. I loved Cena the wrestler, and thought he’d be a horrendous actor because I’d just see John Cena… but he’s ridiculously good at both action and comedy.
Batista is, outside of MCU, very similar to Dwayne for me. But also… it’s Batista. He’s the coolest.