a single swipe of the sword of course isn't enough to put someone of Darkseid great durability away. Evidence indicates that if she used her speed to strike him multipletimes, and used her super human stamina to use it on him repeatedly, not giving his hide or the Mother Box a nanosecond's rest, the story would be much different (she could lasso him and command him to stand stock still while she sliced him to cat meat, another possibility) And you are certainly entitled to your personal opinion that Superman beating Darksied, or Wonder Woman hanging with The Man Of Steel is only because of some kind of favorable writing---but a close look at Kal and Diana's feats, Superman hanging with Darkseid past that writer's tenure, and Diana hanging with Supes up into and during the N52 era, defies your belief.
Now your argument has boiled down to how you think things should play out, not what's happened, what the character has admitted themselves and what the writers think will happen.
Diana has high stats, Darkseid has higher, evidence indicates that he is fully capable of catching people of her speed, not just on the flimsy basis of he's fought Superman but that he is shown fighting at high speeds against Orion and that if he does catch her he crushes her like a grape. People alway's argue that her advantage over Superman has been his vulnerability to magic. Darkseid has no such thing. Now your w**king her lasso, as if thee god of tyranny (subjugating others) who has killed off a planet of martians, been shown immune to Eclipso, will somehow be brought down by her lasso when lesser characters haven't.
She often loses to villains that Superman needs to then defeat, by feats she is Supermans inferior. She will be beaten here as she herself has said at the very beginning of the Darkseid war. There's nothing further to debate.
Never puts up a fight against Hel
Gets beaten by Doomsday both pre and new 52 until Superman saves the day