“For better cameras” like… I don’t see it. Back in the mid 2010s and late 2010s before the bump trend iPhone, Google and Samsung had the best phone cameras, and both were flat and with decent digital zoom and stability (for a phone). If you look at the photo samples for back then and compare it with now the difference is almost imperceptible.
That ugly bump makes big phones even harder to use and weight more now, plus if you’re one of those who never liked using a cover now I bet you’re forced to use one because of the added vulnerability of the bump.
Edit mid 2010s to late 2010s (until the camera bump appears around 2018)
Phone manufacturers are too afraid of making their phone appear thick, instead of making the back flush with the camera and use the extra space for the battery.