If you think about it, that's what all the so called big stars are doing, a complete playback/mime show as they don't want to disappoint their audience, ... according to themselves or more surely the producer.
It's been discussed here before and some agree, some don't.
To me, a live show means taking risks and including mistakes in it and that's, again, to me, what people really want to hear during a live performance and not exactly the same thing perfectly in place without any of these tiny errors that make the show so alive.
And as The Human League used to sing:
I'm only human
Of flesh and blood, I'm made
Human
Born to make mistakes