Out of all the X-Men, Rogue probably has the worst-greatest power of all time. Sure it’s useful to be able to absorb any mutant’s power you want. But prolonged skin contact could result in unconsciousness or even death. Her romantic life is a movie in itself!
Part of Rogue’s dilemma was already covered in the first three X-Men movies, but a more adult-centered Rogue movie could bring up great themes about love, sex, and the attributes we wish we could swap with someone else.