A year or two ago I heard a clip from a live concert Neil Diamond had done and his voice was totally gone.......
I don’t think Mariah can sing the high notes anymore..thus the track and the debacle on New Years Eve.
Though, it is likely she didn’t take care of her voice.
Just as Shirley Bassey had to have taken care of her voice for it still be going pretty strong. Don’t know if she can sing at 80 but she could at 70.