The public does not read reviews.
There's no way to establish whether or not your bet would be valid, because no one is ever given the choice of the exact same phone with only the back material changing.
Correct, because people are not choosing phones based on battery life. In general, most consumers, in the US at least, are buying whichever phone the sales person in the carrier's store tells them to get. But, even if they were making informed decisions, they still are buying a package of features, not picking and choosing which specific features that they want.
See the long post above this one for why this isn't a logical conclusion.
Wireless charging is not a driver of phone sales either. We've already been through a period of most decent phones being made out of metal, Samsung was almost entirely alone in not participating. The build materials will continue to evolve and go in cycles and much of everything that is thrown out there, as explained in the same podcast, is basically a giant beta test/consumer feedback trial trying to find the set of conditions that are going to be most profitable for the OEM.