If they're hearing they won't understand the deaf community, nor need it, and will miss out on what their parents and other community members valued so much
Deafness is a medical issue depriving a human being of a naturally evolved sense that is critical to survival even in a stable civilized world. Denying them that sense because of identity politics is every type of wrong.
2. What you mean to say is denying people the ability to regain their sense of hearing, and the medical interventions you're alluding to don't do that to the extent you're imagining. Our best approaches, cochlear implants: don't restore hearing in the way that removing earplugs would, have a large learning curve; only work on some people; and the affected person's brain usually can't be fully capable of understanding and reproducing spoken language the way a born-hearing person would. People who receive them also still rely on some amount of lip-reading, sign, and apps.
3. People who are adept with sign and familiar with the deaf community often communicate far, far easier with sign language than a hearing person communicating with a deaf/HoH person who has a cochlear implant
To what extent do you actually have knowledge and experience on the topics you're discussing?
You can live without a sense of smell too. But I for one find it extremely useful when a quick sniff tells me some food stuff which otherwise looks fine has actually gone off.
Do you have something resembling a point?