If so, I suggest reaching out to your local Deaf community and spending some time with them. Maybe take an ASL class. You will find that, indeed, there is a unique culture in the Deaf community. You may not end up agreeing that deafness should never be cured, but it will at least give you some context you seem to be missing.
Since you said cochlear implants "already work in many people who are totally deaf" I think you may be missing the most crucial part of one of the quotes you gave: An implant is not a ‘cure’ and an implanted individual is still deaf.
Cochlear implants don't let you hear very well. Most users still rely heavily on lip reading and sign language.
I will give a personal anecdote. I am not deaf, but I have taken ASL classes and engaged with the Deaf community. I met one person who was born totally deaf but got cochlear implants as a child. She cannot converse with hearing people as normal. She is impressively good at lip reading, but still misses a lot of nuance in conversation, and her speaking voice does not sound like a normal person's. So she has been ostracized from social and professional groups. At the same time, she is also ostracized from the Deaf community, because she can't sign as fluently as a child who grew up signing, and the majority of the community is against implants. So she has the worst of both worlds.
So, if I'm correct and your implication is "Obviously deafness should be cured," then I think you may be missing a lot of cultural context and some facts about how the implants work. Perhaps a 100% effective genetic cure would change the discussion somehow, but I'm not sure it changes the cultural implications.