Eeehh, I agree on the prize thing. But it's like paying for a theater play, or a circus act. You are paying for the whole performance package. Stage, wardrobe, lights, dancing troupe, choreography, etc. Not just the music and the artist singing, I go to my local cafe for that sort of shit. For what is worth, pop artists usually include both lip sync and live singing sections in their performance depending on the venue and event type. Like, Taylor Swift has sections of her tour shows where she sings just with her guitar, those are live voice. But asking her to keep a perfect pitch while she is being hurled in the air by acrobatic hydraulics, or while jumping in what is essentially a high intensity aerobic routine is a bit much, no one can do that (OK, maybe Britney in her prime could).
Also, doing a two hour show daily for weeks straight is fucking taxing on the everything. Any touring artists will tell you how demanding and body crushing it can be. The alternative for live singing only shows is that, when the body is unwilling, the show gets cancelled. "You paid hundreds and asked for your vacation time to travel and sleep here tonight? sorry, tough luck. Top artists has a sore throat, we will mail you the refund terms." While artists who lip sync at least some section of their shows can usually tour for longer with fewer cancellations.
That said, this is not an endorsement of Taylor Swift, she is a rich privileged and entitled cunt. But damn she can sing.