Or should a fish be able to breathe without water?

In both cases there are ways to function without fundamentally altering the body, and neither is wrong.

It is not so clear that there is "abuse", when there is an empathetic standard of living.

Now to me, the best argument for taking this is that deaf people do have ears, whether or not they function. So it is reasonable for them to experience sound, but also, they have a right not to, if they so choose.

What I think is harder, if you have experienced neither, to be able to make that decision well. And nobody is talking yet about reversing such a therapy...

Animals that can hear extremely well (owls for instance) rely on this trait to be able to survive.

It's always been more important to us to be able to see versus hear things, we evolved our large brains to take advantage of symbols and information. You can hear a symbol but it requires relatively a lot of energy to relay that over any long distance. In contrast, a smoke signal is visible for many many miles.

Things that are seen tend to be more durable, too. A scream lasts for only an instant, but the signs of a scuffle may last for days or weeks. A carving in stone can last for hundreds of years... and many of the things we eat can be seen but not heard (well).

So it is a far bigger deal to us to be blind than to lack any of the other senses.

This is a valid question. My gripe is people aren't asking the obvious other questions:

1. What are the positive aspects of deafness?

2. What are the different aspects of deafness (neither positive nor negative, but leads to a very different human experience).

If either of these significantly outnumber the negative aspects, I can see why imposing a treatment on children without the parent's consent is problematic.