I still don't know why Apple made the smallest iPhone 16GB and not 32GB/64GB/128GB
I read somewhere that historically, the 32gb model was the most popular size when the options were 16/32/64 and people were willing to spend the middle price point for 32 gb.
So, if the 6 and 6+ were offered in 32/64/128, the people who wanted 32 gb would have gone with the lowest-priced model. By offering 16/64/128, that whole group of people who *would have* bought the 32 just moved back up to the middle range and are all spending $100 more and doubled their storage. The people who want the 16 anyway would have bought the lowest priced model anyway whether it was 16 or 32. And those who would have bought the 64 if it was the biggest size just saved $100 if they went with the middle model but most likely those who had 64 before probably opted for the 128 this time and Apple successfully kept them in the highest price range.
Smart move for Apple and the 16/64/128 strategy is basically a win/win/win situation for everyone.