A shitty camera and shitty lens in fantastic lighting will give good results. The best camera with the best lens in awful lighting will give bad results.
Kind of like microphones, that way. Like how the Apple video was shot on an iPhone (except it had great lighting and a ton of production work), there are hit songs with parts recorded on iPhone. They aren’t advertised like that. But it happens. The advantage of the iPhone is that it’s already in your pocket, and for something as intimate as singing, that proves to be a major, major advantage. Your producer may try to get you to recreate that beautiful performance in the studio, but audio quality doesn’t matter as much when you compare the recording of a good performance to the recording of a much better performance.