Well, literally everyone does. And then there are people who have a loud backing track while singing bits and then have long pauses in between and let the backing track do its job. One isn't better than the other, both are done to spare their voices, which is understandable since its essential for doing their job.
But i also think some of you do a
tad too much. You say she 100% lipped stuff when you cannot be sure at all. Some of you literally just throw in some performances without proof and people agree.
I also know people who worked at the BET / Grammys for the past few years and i know for sure that she rehearses/performs mostly with live vocals.
Also the fact that she sometimes partly lips and sings live at the same time without people noticing proves that she can back it up. And we all know she does...so