I guess I'm missing something - what are the tipoffs to someone using autotune? Not sure what to listen for.
You've heard it a million times, there is no escaping it, you've been hearing it for almost 30 years. It's not just a pitch correction, it smoothens the vocal sound and gives it that digital, artificial sheen. It also takes away expression and mojo.
But let's not forget: Not every artist using autotune can't sing, a lot of them just consider that airey, artificial and smoothened sound de rigueur for a modern pop production.
Rob Halford can no doubt sing/scream in tune and with control,
(recorded in 1989 in pre-autotune days)
yet he is one of the few old guard singers who admits that he uses electronic pitch control live which corrects his singing up to a quarter note (half a half step). He says it gives him less to worry about on an off night and he doesn't want to disappoint people who have paid for a good show. Now crucify him for that.
Re Taylor: I don't think that autotune is the key to her success. She can hold a note though her girlie voice won't win no charisma prize doing it. But even her fans don't rate her as this great singer, Taylor is loved because her fans find her lyrics about (essentially) relationships, struggles and self-doubt relatable, she is everyone's big (wealthy) sister you can ask for advice and help if things aren't running smoothly in your life because she sings about her hiccups too.
That said, I'm no fan of what autotune does to the overall characteristic of a voice, it's like a blender into which you pour your strawberries and cherries for some supposedly delicious mush coming out of it. I prefer my strawberries or cherries whole, even with a little worm once in a while. Yet people love their blenders in the kitchen, don't they?
I'm philosophical about the whole thing: What makes sense for the hit of a dance act where no other instrument is "natural" either, need not apply to Nick Cave. Horses for courses.