Well, I did say she had some moments of weakness, too. I also never said she's hogging the spotlight. There's a lot Sueish stuff about her. Last of her kind, ace fighter, saves the day a lot. She has that backstory and the few moments she went to blindly help Eren, but it still bothers me. Maybe it seems like that because a lot of the other characters have gone through a lot crazier experiences? Just something bugging me.
But she doesn't save the day a lot, that's the thing
If you look at the key events of the story, she really isn't the only or even the major factor in their resolution
During the attack on Trost, she does contribute with her fighting skills to help her friends refill on gas but she needs saving once from titan Eren, and she really doesn't do more than Eren who slaughters countless titans or even Armin who comes up with successful strategies at key moments to save everyone's asses
During the blockading operation, she kills some titans but it's Armin who convinces Eren to pick up that rock and obviously it's Eren who plugs the hole in the wall, and it ends with Rivaille swooping in to save the day
During the expedition outside the walls, sure she contributes to saving Eren but it's Rivaille again who does the biggest part of the job and without him she'd have been killed
And finally when they try to capture Annie, she's the one who cuts her fingers and makes her fall to her doom, but it's Armin who comes up with the strategy and it's Eren in titan form who throws Mikasa in the air because she wouldn't have been fast enough to reach Annie otherwise
So yeah Mikasa does her job and contributes with her particular skills but she doesn't save the day on a regular basis, you could actually argue Armin does it more even if I personally think they're just about equal in their contributions, just in different ways, and that's specifically one of the reasons why this manga is so well written, everyone gets to do something positive making use of their personal talents