Nope! People already claimed the iPhone 4 design to be the worst ever. How could they know it’d become iconic and is considered one of the (if not _the_) best iPhone design(s)
Apple is known to pretty well know it’s users. And most iPhone users probably put a case on the device on day one.
So the quality camera(s) requires a certain thickness (and backside real estate) for technological reasons, but the rest of the case can be thinner, to allow the package of iPhone and case to be reasonably light and thin eventually. The vast majority is happy with that.
The small minority can still get battery cases or power banks, if battery time is insufficient. And if you insist to use your iPhone caseless and want to place it on a table without wobbling: Well, sounds there is a market niche for stickers imitating the bump height, so the iPhone can lay perfectly flat on the table again.
And how about a “pro” version that covers the whole back and only leaves the camera area open?! Now that would sell like hot cakes, I bet! How about marketing it as ... say ... “case” or “back cover”? Yes, that sounds like a plan! Oh wait ...