You don’t need to hear a before and after. Pitch correction leaves artifacts, in the actual sound and with the flattened humanness. The longer you work, the more sensitive your ears will be to picking out the subtleties. They are glaring to me and others like split.
Yes, when not carefully done, it’s pretty obvious, similarly when all breaths are deleted - it all heads towards sterility and artificiality. When comped and adjusted very carefully and musically, I think it’s possible to retain the human voice markers and yet enhance the tuning, keeping the voice in the sweet spots harmonically.
I am all for using the tools at the right times, just handle with care.