I believe I hear pitch correction when it's obviously used, and it's a lot. Pretty much most of the "top forty" pop pablum from the last 20 years. I believe there is pitch correction that I don't spot: the "dark matter" of pitch correction that is done less cheesily.

The worst of it sounds almost like packet loss concealment in a G.722 voice stream: the sustained part of a vocal note basically sounding synthesized.