Gladiator can fly through space including through stars and can one shot planets or at least moons. Gladiator's main gimmick is that he gets more powerful over time as his confidence increases or decreases.
WW is fast for sure but is she interstellar speeds? Since Gladiator flies across entire solar systems in a few minutes at the longest. I am not sure she wouldn't get blitzed, which would just increase his confidence and add to the disparity.
He is also known to have fought several members of the Phoenix Five at the same time and while he lost that force empowered them drastically so keeping up with and fighting them was a big deal. The fact that he can dip inside stars and can with a single punch shatter a celestial body is no small matter.