The cochlear implant debate is a bit more nuanced than that, and it is centered around children. One argument is that, often, the child may not be given a choice whether to be implanted. There are long-term considerations: the CI destroys any residual hearing and the capability for hearing aids to work so you can't "roll back" after the surgery, you can't do MRIs ever again, you are supposed to avoid high pressure/high impact activities (scuba diving, tackle football, etc) -- although many deaf people with CIs that disregard this advice. It's also a big commitment that requires years of auditory training to master, especially if you received the implant after the language development phase of childhood -- maybe 5 or 6 years of age.

It does seem the CI's effectiveness is inversely proportional to age of implantation, especially if you are going from zero hearing (with hearing aids) to a CI overnight. The younger you are, your brain has a chance to develop into the CI as it would with normal ears, and those kids are often functionally hearing. Which is totally fine with me, by the way.

Source: Deaf, use sign language, have a CI, although I don't wear it anymore. Me and my friends with CIs are no less a part of deaf culture because of it.