God, I think I've read exactly one decent story with that pairing and it was entirely by accident. Clicked expecting something fluffy and domestic, got hit with this incredibly heavy character study about grief and the ghosts we make of our mothers. It wasn't even romantic in a traditional sense? More about Izuku, years after All Might's era, inheriting a broken system and realizing Inko’s quiet, fearful love was the first 'quirkless' heroism he ever witnessed. The emotional bond gets explored through absence—her death, his regret, the way he starts making her favorite tea out of habit in a silent apartment.
A lot of the other stuff I've glimpsed leans into hurt/comfort tropes so hard they snap. Sickfics where he's quirkless and bedridden, villain AUs where she's the only one who visits Tartarus. The bond becomes this infinite well of unconditional acceptance, which can feel saccharine, but sometimes that's exactly the blank check of comfort a reader wants. The dynamic reverses canon; he's not her brave little boy, he's her entire world needing protection, and she’s powerless to give it, which twists the knife.