50 Shades wouldn't be any different because E L James wouldn't have written it any differently or put in the leg work to make it any good, but good omegaverse fics are pretty world building heavy and massively diverse. For instance, many omegaverse writers don't just substitute alpha=male and omega=female. Give that basic premise to an omegaverse writer to change up and watch the power dynamics becomes fascinating as you deal with things like omega!Christian proving himelf in an alpha dominated world or an alpha!Anna handling not being as dominant as she's expected to be. Hell, there's a trend for omega tilted omegaverse putting all the power in the hands of omegas who can make alphas lose control, it's a kinda fascinating trend that's depicting more and more alphas are animalistic and treated as mindless beasts, or beta heavy societies, because of course the ones who don't lose control are in charge in society. Or the ones that focus heavy on pack dynamics aka you don't just date the omega, you have an entire found family to prove yourself to and find your place in. Boiling oemgaverse down to men getting pregnant and sexism (things not all omegaverse has and opinions are varied) is like boiling fantasy down to dragons and dwarf vs elf fantasy racism. Also, a hell of a lot of straight omegaverse has roots in werewolf/shifter romance, more than the fanfic slash works. In many ways, they're two similar but seperate categories that sort of converged.
As for the actual question: the part where they either get together in the last five minutes as the credits roll, bonus points for little to no actual romance, or they got together in a time skip and you expect me to just be ok with this in the epilogue despite their lack of interest in each other, or even worse despite one person saying no pre-timeskip. It's a joke that he just finds this girl so beautiful but she's so out of his league but he's persistent and then post timeskip they're married, like what? I just want chemistry, please.