Personally, I feel the above headline is clickbait. Actually, when I see some of these clips, I am amazed at how professionally these performers went on with the show. Beyonce getting her hair stuck in a big fan onstage and keeps on singing while her guards cut her hair loose! Britney Beyonce gets her hair stuck in a stage fan. Britney's costume breaks and she has to keep on singing while keeping her chest covered. And lots of falls where they get right back up and keep on performing.
Then there are all of the lip-syncing problems. Which I actually have come to expect. Look, have YOU ever performed in an on-stage musical with msuic, dancing and choreography? Then you KNOW it ain't easy, friends! A show is entertainment, and I don't care how physically fit the performer is, if they are doing all of that choreography and flying over the crowd on a cherry picker and such, then their performance will suffer if they have to sing, too. I say, let 'em sync!