Cheat Code #2 for accommodating disabled characters in sci-fi/fantasy:
How you aid a disability depends on if it's a new development or had always existed.
i.e.: If someone's lost their legs to a griffin biting them off last week, giving them steampunk prosthetic legs is a good aid. There's something they can't do, that they very recently could, that they need to learn to work around. The prosthetic legs still need an adjustment period to learn how to use them, but your character knows how legs should work and can figure it out more easily.
If someone lost their legs because, as a child, they wandered away from the space field trip and got partially eaten by a carnivorous plant, then it depends. Prosthetic legs can technically work, but the longer the character was without legs, the harder it'll be to re-learn how to use them. You might want to go with bionic legs for short distances, but a hover chair for daily use.
If someone was born without legs, then prosthetic legs are more hindrance than they're worth. Your character has never had legs, and has no idea how they're supposed to work.
Imagine if you're in a world of centaurs; you're given prosthetic hind legs, and now expected to be able to climb up cliffs with the grace of a mountain goat. It's a whole new skill you'd have to learn, and you would get annoyed with it very fast; how are they supposed to sync with the legs you already have? How are you supposed to balance? You can't feel anything, you don't know how much space it occupies.
Someone who's always been disabled doesn't need the thing they were born without, they need aid that lets them do what everyone else can in a way they're familiar with. If your character has always been deaf, glasses with subtitles appearing on them are infinitely more useful than aids that let them hear, because hearing when you've always had silence is going to have a steep learning curve and be ridiculously overwhelming.
Try to give them something they're used to.
Note: This is different with very small children, because they're already learning how to use every part of them. If a toddler in your sci-fi was born without legs, they can be taught to use bionic legs at a very young age, but it has to start early or it'll run into the problems above.
Cheat code 1: How to avoid eliminating disability in your setting
Cheat Code 3: How to make your setting itself disability-friendly
